Thank you very much for that,(should have found it myself), exactly what I needed.

I realize that it's pretty steep and short after fire forming, but in all the drawings I have found for the WT, none specify the shoulder datum point.

My Hornady Headspace Gauge, 5 bushing set either rides high or low, but not in the middle of the shoulder.

I'm trying to determine whether my dies or barrel are goofy. After making new brass from 1-fired LC 5.56 brass, with the sizing die set to just touch the shell holder, the shoulder seems to be .025 back from where it ends up after fire forming. I realize that's part of what fire forming is about, but resizing those fire formed cases pushes the shoulder back .025 again. That's a lot more than other bottleneck case calibers I reload for and all the working can not be good for the brass.

To be absolutely sure of my readings, I was going to turn a bushing on my lathe that hits that datum point, but I can't without knowing what the diameter should be. FWIW, both the high riding and low riding bushings from the set show the same .025 setback after resizing.

Thanks,

Hoot

Your questions may be better directed to Wilson's customer service if you think you are having a barrel or die problem,  but I can offer what we've seen with the x40 over the years....

The barrels and dies that I had manufactured were sent out with a "7.62x40mm overview" pamphlet that addresses a few of the things  you may be seeing....

One of the suggested set-ups in the pamphlet is to run the sizing die down to the shellholder on ram extension, and then back it off in increments until a test piece of brass is formed that 'will not chamber', that lets you know the outerlimit of headspace.....

From there you can use feeler gauges or shim stock to measure from the face of the shellholder to the base of the sizing die to record the outerlimit for formed brass that will not chamber.....then the sizing die can be turned in fine increments downward until a formed piece of brass will chamber...take that measurement and that will give the set-up height for producing brass that headspaces for your 'bolt-chamber-die-shellholder' combination....I usually also create some inert chambering dummies with the bullets I intend to shoot, as loading the bullet in the neck can have a slight impact on headspace from opening the shoulder a little.....

The change in shoulder datum point from die-formed to fire-formed brass is common, and can be seen in other cartridges with a small shoulder like 300-221, 416 Rigby, etc....this is from the sizing die creating a more radiused or rounded shoulder during the forming process - then taking on the more angular shape of the chamber once fire-formed....

Without having everything in front of me....my internet guess would be that most of what you're seeing could be cleared up by adjusting the sizing die for your 'bolt-chamber-die-shellholder' combination.....

Thanks for your observations. The backing off of the die process was exactly how I approached this caliber. It's how I do all my bottleneck calibers I load for. However it appears to work differently in this caliber. Rather than retype what I already posted in the Wilson sub-forum, Here's the Link to it.

I'd value your opinion once having read it. The reply from Wilson was not enlightening.

Thanks again,

Hoot

Hi Hoot,

It's common to see the datum point you're referring to change from die-forming to fire-forming....as each process produce different shaped shoulders....

With any die formed cartridge, when the sizing die is set to produce correctly headspaced die-formed brass it should be 0.000" to 0.001"interference to crush fit for an auto-loader....if the die-formed brass is then fire-formed, the shoulder pushes forward and takes on the shape of the chamber.....if the sizing die is left at the original setting, and isn't lifted to allow for the change in datum point the brass will just be returned to the original die-formed dimensions - defeating the fire-forming step.....and depending on the cartridge, brass thickness, shoulder angle, and case to neck differential - that datum point can change 0.100" between die-forming and fire-forming....and if the sizing die isn't moved to the fire-formed dimension, the brass will just be exercised back and forth between die-formed and fire-formed dimensions.....

I agree wholeheartedly. I am a good reloader, but apparently not a good communicator..

I tried pushing the fire formed case shoulders back only 4-5 mils and got an easy fit in the chamber, but the same load recipes that ran flawless and accurate in the newly formed brass, showed worrisome pressure signs when shot in the fire formed cases. I don't want to have to push the fire formed case shoulders back .025 like the newly formed cases, but if I do not do that, I encounter higher pressure. I know it's counter-intuitive since the fire formed cases have greater powder capacity.

My impression was that the newly formed cases tolerated my charge because the energy expended fire forming them to my chamber, served as a form of buffer to the pressure curve. The fire formed cases, with their shoulders only pushed back 4-5 mils do not have the benefit of that redirected energy. When I push the same fire formed case shoulders back the full .025, they work fine, hence my opinion that this caliber relies upon the cases eating up some of the initial energy released, when running loads near the upper limits. Again, it goes against my experiences these past 35 years reloading for many other calibers. It is however, what I am observing. I'm at a loss to explain it, just postulate what may be the cause.

Slower powders like 1680 do not encounter this issue. Not that 300MP is a racehorse powder. It's about the same speed as IMR4227, but with more energy density, hence my interest in it for the lighter bullets in this caliber. Even with my 20" barrel, 1680 IMHO is too slow to be optimum for 110gr bullets.

The good news is I'm still on the plus side of the learning curve for this caliber. IE the fun side. I will continue to pursue furthering my understanding of it, possibly finding a truffle buried somewhere along the way. I encourage owners to give 300MP a try with the 110gr bullets. Start down at 22gr and work up from there. It may just be that truffle.

Hoot

thanks for the info on 300mp, i am going to get some to try. as of now 1680 is the only powder that will reliably cycle my 18". i have ran imr 4227 and h110 to dangerous levels and still wouldn't pick up next round. but 1680 is a laser with 110 bullets for me

here is my go to load for the 110 hornady sp running 2580-2600 fps shoots the same in fresh or fire form cases these three were off bipod rapid fire 100 yards. was my test shots from last weekend - was running some 110 sierra hp loads to find my go to load.

I've shot the 300MP in other cartridges but not the x40...like you said it's close to 4227....

Small capacity changes can make a huge difference in pressure, pressure symptoms, velocity and the like.....especially at max loads for a powder, small things like seating depth, variations in case size, primer performance - some counter intuitive, but traceable occurrences can be seen...

One in particular as loads and velocities are increased, the velocity in feet per second per grain, or tenth of a grain, of powder will usually increase per grain of powder  - then begin to get less per grain of powder added - at some point stop gaining velocity as powder is added - and in some cases the velocity will start to reverse as more powder is added....this is based off the capabilities of the powder and how it responds to pressure....

Indicators of pressure on the cases and primers can also be tracked along with the above example...brass will look good - start to show signs of pressure - start to look real nasty - and as the powder stops performing and possibly go into reversal, the brass starts to look good again....

So if you're at that point where the smaller die-formed case volume is putting enough pressure on the powder to make it stop performing, or potentially reverse,  the brass may look completely fine -  if a fire-formed higher volume case is used with the same load, it backs the internal pressure down to that level right before reversal where the powder starts working again and the brass starts to look nasty....

Nice 100yd group. I don't know if it's the twist of the barrel, the OBT of the barrel or what, but so far the 110gr bullets outperform any 125s or 130s and 140s I've tried. I have not tried the 125 Hornady SPs yet, but I did try their 130's. Too long and the sharp ogive makes you seat them so deep to keep them out of the lands that they rob too much powder capacity. I'd like to try the 110 Vmax, but they are like unobtanium locally. I mistakenly bought a box of the Barnes TAC-TX for the 300 BO. The ones with the incredibly long black ballistic tips, to try with the WT. OK, we all make mistakes. They're sitting in my "trading stock" drawer now. Would like to try some of the new ones specifically for the WT if Wilson ever gets any in stock. The craziness of reloading components supply is getting old...

WRT the other post. Yes, I have seen velocity flat-topping with increased charges also over the years. Actually recently experimenting with my other lunatic fringe AR15 caliber, the 450 Bushmaster. Usually when I'm running a higher energy content, but slower burning powder than is optimal for the bullet weight I'm loading for. The WT should prove an interesting caliber to experiment with for some time to come. Tripledeuce has one also and recommended experimenting with pushing the shoulder back more than the 4-5mils I've tried so far, but not all the way back to where it goes with the die screwed down to the shell holder, in an attempt to find a possible sweet spot between both extremes. With the Sierra 110 HP's, I've been running them at 2.125 COL, which coincides with .010 off the lands in my chamber. I may try giving them more of a running start also. Hate to mess with a recipe that throws .3-.5 MOA groups though.

Thanks for the input guys.

Hoot

You'll probably find an agreeing sentiment bout page 3 of this thread

Well...maybe not that early, we were probably still arguing about Mini14s....but it was pretty early....

Why is it that the blacktips are not useable? Length when loaded?

What are you looking to trade for? I have two boxes of Nosler 125 BT greentips to trade off.

Yes, at 2.26 COL, the ogive is down inside the neck. Some reloaders don't care about that, but I do.

I'd trade them to someone with a 300 BO for a box of the correct 110 TTSX FB. I appreciate the thought as I like NBTs in other calibers. However, IMHO, the last thing this caliber needs is a boat tailed bullet.

When I get some more Sierra 110gr HP, I will try some runs with different degrees of shoulder setback, starting with what you get with the die screwed down to the shell holder and see where the pressure signs start to show up. I'll write them up in a Range Report and post them here. Judging from it's size, I assume this is the thread for discussing anything related to the WT?

Hoot

I may have some 110 gr TSX's at home I'd trade, but none of the TTSX's, if that would interest you at all.  I'll try to remember to check when I get home.

I am shooting mostly with the Encores these days, so I load the Barnes 110g Tac-Tx blacktips to the optimum distance off the lands in my 300blk(very little in the neck), in my newest barrel chambered in 30RAR, and I plan to do so when I get my existing 300blk barrel rechambered to 762x40WT.

The blacktips look wicked in the 30RAR!

Sure, why not? These are useless to me. PM me if you find them..

Hoot

I always liked the 30 RAR. I did not know it had a following outside the AR15 platform though.
This may sound like heresy here, but I already looked into whether the WT could be re-chambered in 30HRT. Unfortunately the WT is a little too long at the shoulder.

Hoot

Just an fyi...the 7.62x40 can be rechambered to 30HRT....I've done a couple if still interested....

I stand corrected. The fellow who told me that actually chambers rifle barrels, so I took him at his word on it.

Hoot

We've been know to chamber a barrel from time to time

There's roughly 0.036" between the two.....the 7.62x40 being longer....

The gas block placement / gas system on the AR has roughly 0.100" play in it....meaning: the gas tube can go up to 0.100" deeper into the gas carrier key on most systems with no ill effects....

By spinning off the extension, re-profiling the extension tennon to allow one additional turn on the extension, the original chamber is shortened by roughly 0.062"....well inside the 0.036" difference of the two cartridges and also inside the 0.100" tolerance of the gas system...

for this reason, when we contour our barrels, the gas block seat is placed at the farthest forward position for the system length to allow the extension removal, and one turn profiling up to two times...

On the 30RAR the non-standard rim dia makes it less desirable for bolt guns, but for Encores the rim dia means squat. so after checking the round out recently, It was close enough to what I was scheming to make from my 450B brass to be a no-brainer. Should make an excellent deer rifle with the Barnes 130g TTSX, 18" 1 in 10 twist barrel. I have shot a few whistle pigs with the blacktips, flea off a gnats ass accurate at 200 yards.

On the Encore: we have reamers for a 35RAR and 375RAR

Probably gonna be a couple of my next builds....

Trust Hornady and Bushmaster to get together and change a cartridge spec that started out originally designed with a .472 rim into .466. Makes it just a little more inconvenient to try and make your own brass from .284 Winchester without having to turn every stinking rim and extraction groove down. I know, I've been there.

WRT the 30 HRT. So it's not just a simple re-ream like with the 300 BO. My gunsmith friend must have meant it could not be simply done.

Hoot

lol lol....either way it's just metal shavings on the bench.....removing an extension takes a 1/4" chisel and an extension wrench....you can take an extension off a barrel easier than it'll take to get the barrel out of the receiver....

If that poses a problem to an AR / barrel smith......

I have a beautiful 7.62x45 takeoff barrel that came off a friend bench rest gun.  It was shooting into the .2 & .3's when it was removed and has about 1500 rounds through it.  It is a bull barrel and has plenty pf room in front of the chamber to have the barrel reconfigured into an AR contour / platform.  Do you know of anyone that can perform this operation?  It is a 1x13.5 (I think).  I think it would make a great 7.62x40 / 30ARA or 7.62x39 barrel....I just need to find a smaller machinist to do the work.  All the larger companies are much too busy to take this on.

Bill in OR

Here's a thread for an upper we're building doing what you described except in 300 Blackout....using a take-off barrel

We've made a local niche for ourselves by doing odd or labor intensive stuff other shops don't want to mess with...wildcats, non standard lengths, odd configurations, twin gas blocks, etc.....

Keep most popular AR chamber reamers on hand, and lots of wildcats....

Have you seen or heard of Eagle View arms? They specialize in TC's and are currently working on releasing machined Encore stubs, I have several "shot out" Krieger barrels that are screaming for new homes,,,LOL  http://www.eagleviewarms.com/?wpsc-product=ev-arms-encore-stub

that is friggin sweet!!!!

I had heard of a monolith block being made but could never run-down a manufacturer name.....

Right click....bookmark page......aaaaand save

Thanks!!

The EVA stubs will really open up the TC smithing world to precision shooting, welding that lug on always distorts barrels.

Also Bellm TC has unchambered Bergara barrels for sale if you just want unchambered TC Encore barrels. I really like the accuracy of the Begara barrels and they clean up easily after shooting all copper bullets.

The Bergara barrel I have chambered for 300blk is a sweet shooter, 13.5" barrel shooting sub 1/2" groups at 100 yards shooting supers OR SUBS off a bipod! All the guys at the hunting club had expected a more shotgun type grouping from this stubby truck gun, LOL

Ballpark cost and are you willing to take this on?  You have me excited now!  My email: [email protected]

Bill

E-mail returned.....

[email protected]

I'll PM you later if that does not work.

Bill in OR

I just wanted to add that i ran some 110 30 carbine bullets this weekend, 5 strings of 5 rapid fire with zero feed issues and i ran them down to 2200 fps and up to 2400 fps.

accuracy was about what i expected 1.5-2 inches at 100.

I am going to use them for my plinking and fire form loads.

Sounds like a good Idea for cheap plinking/fireforming...What was you COL for those loads ?

I load them to 2.02 they are touching lands at 2.05 in my barrel.  i ran tests to see what jump did and .030 seemed the best. i went from .010 - .020 then to .030

if you check in the workbook i sent you there is more data in there from a year ago when i did my first work ups.

It worked good......and I received your reply....

Will keep a lookout for the specs....

Right now I've got about a two month backlog, but I recently built a few uppers for members here that got out in a little less time than that......

Thanks for the update, now finding some in stock is the challenge...

Just because I could;

I was cleaning up the 500 yard line at my range yesterday and thought I should play a bit.  The .308 bolt gun did its job but then I pulled out the 7.62x40 just for laughs.
16" barrel and a 1.25-4 Leupold VXR scope.
Five shots at a 8" gong, 4 hits just using my range bag as a rest.
I would never use it on game at that distance, but it was fun.

correct answer is a 8 or 10" barrel w/ appropiate twist rate and a pinned  short low pro gas block.

I cut and pasted everything I could find on this cartridge from the internet (I got it off the internet...gotta be god right?? lol)  

Be forewarned that I do not have my dies yet and I HAVE NOT used any of these suggested loads.  I am only putting it out there for you to rummage through.  It contains some powders that I no longer have access to because of the current shortage; it also has some powders listed  that I just happen to have on the shelf.  

DO NOT consider that these load are an endorsement.  I will publish my load workups after I get to the range and wring out this cartridge.  You will recognize some of these as having been posted from some regular contributors in the past.  

The 5.56 case is shortened to 1.560”

Here is the Wilson data:

7.62x40 WT Handload Data
110 gr. Sierra Hollow Point
21 gr. Hodgdon H110
Lake City Formed Case
Remington 7 ½
2.110” OAL

110 gr. Barnes TTSX
21 gr. Hodgdon H110 (16” Barrels or Shorter)
Lake City Formed Case
Remington 7 ½
2.250” OAL

110 gr. Barnes TTSX
25 gr. Accurate 1680 (16” Barrels or Longer)
Lake City Formed Case
Remington 7 ½
2.250” OAL

125 gr. Sierra Pro Hunter
25.5 gr. Accurate 1680
Lake City Formed Case
Remington 7 ½
2.160” OAL
125 gr. Speer TNT
25.5 gr. Accurate 1680
Lake City Formed Case
Remington 7 ½
2.250” OAL

125 gr. Nosler Ballistic Hunter
25 gr. Accurate 1680
Lake City Formed Case
Remington 7 ½
2.250” OAL

7.62x40mm 16" 1:8 Olmypic .078 gas port carbine length gas system, fire-formed brass...

125 TNT 21.5gr H4227 = 2,230 fps
125 TNT 22.0gr H4227 = 2,350 fps
125 TNT 22.5gr H4227 = 2,440 fps
125 TNT 25.8gr 1680 = 2,430 fps
125 TNT 22gr lil-gun = 2,540 fps
125 TNT 22gr H110 = 2,480 fps
125 TNT 22gr W296 = 2,475 fps

135 SMK 19gr W296 = 2,211 fps
135 SMK 19.5gr W296 = 2,270 fps
135 SMK 20gr W296 = 2,310 fps
135 SMK 20.5gr W296 = 2,350 fps

155 SMK 17gr H4227 = 1,915 fps
155 SMK 17.5gr H4227 = 1,970 fps
155 SMK 18gr H4227 = 2,010 fps
155 SMK 18.5gr H4227 = 2,050 fps
155 SMK 18.8gr H4227 = 2,072 fps
155 SMK 19gr H4227 = 2,095 fps


My favorite loads right now are the:

125 TNT 22.5gr H4227 = 2,440 fps
135 SMK 20.5gr W296 = 2,350 fps.....going to try the 135's with the 4227 this weekend.
155 SMK 19gr H4227 = 2,095 fps.... 320 Major Power Factor with a 16" barrel.....WoooooooHoooooo

7.62x40mm 16" 1:8 Olmypic .078 gas port carbine length gas system, fire-formed brass...

135 SMK 19gr H4227 = 2,149 fps
135 SMK 19.5gr H4227 = 2,190 fps
135 SMK 20gr H4227 = 2,240 fps
135 SMK 20.5gr H4227 = 2,278 fps
135 SMK 21gr H4227 = 2,312 fps
135 SMK 21.5gr H4227 = 2,330 fps
135 SMK 22gr H4227 = 2,361 fps

A while back Bill Wilson mentioned (I believe in this thread) that H110 and W296 were the same. I don't know that for sure so I would recommend that you verify that information, but I have load data with 296 from a 16" mid gas barrel that may be helpful. When I get home I'll try to remember to post it. It is buried in this thread somewhere but not sure where. I've had very good luck with W296 and 110gr projectiles so I see no reason to wait for 1680.

ETA: On page 23 I have some load data for W296. In my 16" mid gas barrel 22 grains of W296 took the 110gr V-Max to 2550fps and 21 grains of W296 took the 125 Nosler BT to 2400fps. Page 29 of this thread is where Bill said he confirmed that H110 and W296 are the same powder. As always, if you use that information start low and work up slow.

125g Nosler - 19.0g of 5744

130g Barnes TTSX - 17.0g of 5744
From the AR15 forum 06-13:
Cartridge          : 7.62 x 40 WT

Bullet             : .308, 110, Hornady SP 3010

Useable Case Capaci: 28.643 grain H2O = 1.860 cm³

Cartridge O.A.L. L6: 2.260 inch = 57.40 mm

Barrel Length      : 18.0 inch = 457.2 mm

Powder             : Accurate 5744



Predicted data by increasing and decreasing the given charge,

incremented in steps of 1.255% of nominal charge.

CAUTION: Figures exceed maximum and minimum recommended loads !



Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time

%       %    Grains   fps   ft.lbs    psi    psi      %        ms



-12.6   85    20.90   2299    1290   38255   5011     92.6    1.008

-11.3   86    21.20   2328    1324   39691   5089     93.1    0.991

-10.0   87    21.50   2357    1357   41176   5165     93.6    0.975

-08.8   88    21.80   2386    1391   42712   5239     94.2    0.959

-07.5   90    22.10   2415    1425   44299   5312     94.6    0.944

-06.3   91    22.40   2444    1459   45942   5383     95.1    0.929

-05.0   92    22.70   2473    1494   47640   5453     95.6    0.914  ! Near Maximum !

-03.8   93    23.00   2502    1529   49398   5520     96.0    0.900  ! Near Maximum !

-02.5   94    23.30   2531    1564   51216   5586     96.4    0.886  ! Near Maximum !

-01.3   96    23.60   2559    1600   53098   5650     96.8    0.872  ! Near Maximum !

+00.0   97    23.90   2588    1636   55046   5712     97.1    0.859  !DANGEROUS LOAD-DO NOT USE!

+01.3   98    24.20   2616    1672   57064   5772     97.5    0.846  !DANGEROUS LOAD-DO NOT USE!

+02.5   99    24.50   2644    1708   59153   5830     97.8    0.833  !DANGEROUS LOAD-DO NOT USE!

+03.8  100    24.80   2673    1745   61318   5885     98.1    0.821  !DANGEROUS LOAD-DO NOT USE!

+05.0  102    25.10   2701    1782   63561   5938     98.3    0.809  !DANGEROUS LOAD-DO NOT USE!

+06.3  103    25.40   2729    1819   65886   5989     98.6    0.797  !DANGEROUS LOAD-DO NOT USE!



Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge

Data for burning rate increased by 5% relative to nominal value:

+Ba     97    23.90   2642    1705   59145   5727     98.8    0.833  !DANGEROUS LOAD-DO NOT USE!

Data for burning rate decreased by 5% relative to nominal value:

-Ba     97    23.90   2526    1559   50988   5645     94.7    0.888  ! Near Maximum !


Cartridge          : 7.62 x 40 WT

Bullet             : .308, 125, Sierra SP 2120

Useable Case Capaci: 26.353 grain H2O = 1.711 cm³

Cartridge O.A.L. L6: 2.200 inch = 55.88 mm

Barrel Length      : 18.0 inch = 457.2 mm

Powder             : Accurate 5744



Predicted data by increasing and decreasing the given charge,

incremented in steps of 1.364% of nominal charge.

CAUTION: Figures exceed maximum and minimum recommended loads !



Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time

%       %    Grains   fps   ft.lbs    psi    psi      %        ms



-13.6   84    19.00   2118    1246   37672   4633     93.4    1.083

-12.3   85    19.30   2148    1281   39207   4711     94.0    1.063

-10.9   86    19.60   2177    1316   40799   4787     94.5    1.044

-09.5   88    19.90   2206    1351   42448   4861     95.0    1.026

-08.2   89    20.20   2235    1387   44159   4933     95.5    1.009

-06.8   90    20.50   2264    1423   45932   5003     95.9    0.991

-05.5   92    20.80   2293    1460   47771   5072     96.4    0.974  ! Near Maximum !

-04.1   93    21.10   2322    1497   49678   5138     96.8    0.958  ! Near Maximum !

-02.7   94    21.40   2351    1534   51657   5202     97.2    0.942  ! Near Maximum !

-01.4   96    21.70   2379    1571   53711   5265     97.5    0.927  ! Near Maximum !

+00.0   97    22.00   2408    1609   55843   5325     97.9    0.912  !DANGEROUS LOAD-DO NOT USE!

+01.4   98    22.30   2436    1647   58057   5382     98.2    0.897  !DANGEROUS LOAD-DO NOT USE!

+02.7  100    22.60   2464    1685   60356   5437     98.5    0.882  !DANGEROUS LOAD-DO NOT USE!

+04.1  101    22.90   2492    1724   62745   5490     98.7    0.868  !DANGEROUS LOAD-DO NOT USE!

+05.5  102    23.20   2520    1762   65228   5541     99.0    0.855  !DANGEROUS LOAD-DO NOT USE!

+06.8  103    23.50   2548    1801   67809   5588     99.2    0.841  !DANGEROUS LOAD-DO NOT USE!



Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge

Data for burning rate increased by 5% relative to nominal value:

+Ba     97    22.00   2455    1673   59989   5317     99.3    0.885  !DANGEROUS LOAD-DO NOT USE!

Data for burning rate decreased by 5% relative to nominal value:

-Ba     97    22.00   2352    1536   51735   5283     95.7    0.942  ! Near Maximum !

125 sierra 21.5g IMR 4227 , 135 sierra 21.5g IMR 4227, 110 TTSX 22g IMR 4227, 155 TTSX IMR 4227 and 110 round nose 22g IMR 4227. Dont remember the FPS but ill post that info tomorrow.

getting ready to start putting some test loads together.

wilson lists data for sierra, barnes and nosler 110 and 125gn bullets but I couldn't find the sierra's around here but i found

hornady 110 vmax's and hornady 130 soft points.

does any one have some load data for these bullets?

if not i will start 10% below the comparable bullets on wilson's load sheet.

they list aa 1680 for the powder so i picked up 3 lbs.

i will be loading them for a 18" tatical hunter standard rifling barrel.


here is the wilson data:

7.62x40 WT Handload Data
110 gr. Sierra Hollow Point
21 gr. Hodgdon H110
Lake City Formed Case
Remington 7 ½
2.110” OAL

110 gr. Barnes TTSX
21 gr. Hodgdon H110 (16” Barrels or Shorter)
Lake City Formed Case
Remington 7 ½
2.250” OAL

110 gr. Barnes TTSX
25 gr. Accurate 1680 (16” Barrels or Longer)
Lake City Formed Case
Remington 7 ½
2.250” OAL

125 gr. Sierra Pro Hunter
25.5 gr. Accurate 1680
Lake City Formed Case
Remington 7 ½
2.160” OAL
125 gr. Speer TNT
25.5 gr. Accurate 1680
Lake City Formed Case
Remington 7 ½
2.250” OAL

125 gr. Nosler Ballistic Hunter
25 gr. Accurate 1680
Lake City Formed Case
Remington 7 ½
2.250” OAL

Center top was my Son's first three shots out of the new barrel. Then he started adjusting the sights and got it centered. Load was 21.0gr. Win. 296, Rem 7 1/2, and Sierra 110gr. HP. Small target on upper right were then my first five shots and upper left were his next five shots. That load averaged 2,494 fps. with a standard deviation of about 40fps. which I can certainly tweek on down a bit with more test loads. This load was taken from Wilson's chart.
Fired some more today and fired the same charge of powder with another box of old bullets that I had on hand. Win. 110gr. PSP. They gave about identical point of impact as the other two bullets tried last week.

My Son worked his magazines over just a bit with a file and they worked better. The ribs on either side of the magazine about where the shoulder of the .223 case meets the neck have to be filed down some. Apparently the ribs help prevent the .223 bullet from working too far forward in the magazine under recoil or something.

The 30 rd magazines worked perfect after they reached the 20 round mark, but he will have to still remove a bit more from the bottom of the magazines down where the bullets rub when 30 rds are loaded since he had only filed down the top half of the magazine's side ribs. It does not take all that much, but it apparently must be altered a bit all the way to the bottom.
This one has a few millimeters longer case than the Black Out. It is not really intended to be shot sub sonic, although with a very fast twist and probably 220gr. bullets it could go sub sonic.

This case is made by only trimming off the neck of the .223 case at the shoulder and then just sizing through a full length sizing die. I understand that the Black Out is cut off at about the rear of the shoulder.

We have found that cycling is very critical of the amount of gas pressure from the gas port and with too fast a powder, it sometimes can cause a short stroke from too small amount of gas impulse and failure to pick up the next round.

At first, we thought it was the reported magazine problems, but now, I feel that getting the proper gas pressure at the port is mostly the problem that others have been blaming on the magazines. We are planning on sticking to 125-130gr. bullets, so our powder will change from 296 with the 110gr. to probably 1680 with the heavier bullets and the rifle reportedly cycles well with that powder bullet combination.

It shows promise of great accuracy as we have really not worked up any load for it, but only used the recommended load from Wilson and it did shoot great. I suspect that when all is said and done after I set down and work of the exact load for this rifle, that it will be a great shooting little booger. Should smack a deer about like a 30-30.

Cartridge Specifics - The 7.62x40 WT is based on the inexpensive and readily available 5.56x45 Nato cartridge case. The 5.56 case is shortened to 1.560” and then re-sized (single operation) in a standard 7.62x40 WT sizing die which results in a formed 7.62x40 WT case with a finished overall case length of 1.565”. The cartridge is designed for 110-150gr .308” diameter bullets loaded to supersonic velocities, but if chambered in a 1-8 twist barrel is also suitable for heavy bullet subsonic use also.

Ballistic Performance Comparison

7.62x40 WT (16” barrel)
110gr: 2450FPS Muzzle Velocity and 1466 Foot Pounds of Energy
125gr: 2400FPS Muzzle Velocity and 1599 Foot Pounds of Energy
150gr: 2200FPS Muzzle Velocity and 1612 Foot Pounds of Energy

5.56 Nato (16” barrel)
55gr: 3150FPS Muzzle Velocity and 1212 Foot Pounds of Energy
62gr: 3000FPS Muzzle Velocity and 1239 Foot Pounds of Energy
77gr: 2750FPS Muzzle Velocity and 1293 Foot Pounds of Energy

7.62x39 (16” barrel)
123gr: 2320FPS Muzzle Velocity and 1470 Foot Pounds of Energy

6.8 SPC (16” barrel)
110gr: 2550FPS Muzzle Velocity and 1594 Foot Pounds of Energy

300 BLACKOUT (16” barrel)
125gr: 2275FPS Muzzle Velocity and 1436 Foot Pounds of Energy





Bill in OR

I've been reloading my own 40wt rounds and had great success with 110-gr and 125-gr rounds but was wanting to know if anyone has loaded 150-gr rounds and if so what powder would be best?
Thanks, Aaron

I you are waiting for dies (like I am) here is Wilson Combats response to my inquiry:

Tera Hadley

Tera Hadley (Wilson Combat Support)

Jun 27 11:05 (CDT)

Hello William,
We have not received our shipment from the suppler that was due 5-15,
so I apologize I do not have an ETA at this time.
We currently have 16 units on back order and your order is number 8.

In for a 20" barrel ,dies and some new cases.
Cant wait to try it out!

BUMP  I don't want this to go to the archives before my back ordered barrel and dies get here.

We will post some pics of our X40 WT build...hardest part seems to be getting/finding some AA1680 powder...This round is a great alternative to the X39mm Russian.

We call it a American ARK...Thanks Kurt for such a nice round, and to Wilson Combat/Tactical for their great products.

I got so tired of having a complete upper....and not being able to get a set of dies from Wilson that I think I'll be giving up.  Kurt built a REALLY accurate 7.62x39 for me so having the 7.62x40mmm may be redundant.  My new unfired 1x12 poly bbl just may head off to E-bay.  I called Wilson and told them to cancel my die order.  Too bad, I was looking forward to working with the 7.62x40mm.

Bill

A member here contacted me recently about building a x40 hunting upper with a little more 'bite' for some open property he hunts in East Texas...

The bullets he will primarily be using are the 125 TNT for plinking and the 110 TSX and V-MAX for hunting.....

Ended up putting together a 22" rifle-length gas system 1:14 twist 'pencil' weight barrel.....

Ran several different loads using the above mentioned bullets with much success....

As mentioned earlier in this thread, the 125 TNT and 110 TSX velocities track almost identical to each other in part due to the monolithic construction of the TSX.....the TSX was also the slowest of the 110s ran today.....

The 125 TNT and 110 TSX were clocking ~ 2,700 fps and the 110 V-MAX was clocking ~ 2,800 fps....





A little finish work and it will be ready in plenty of time for hunting season....

Kurt, what powders have you found to work well with the x40mm round with a rifle gas system ?

The only powders I have available is H4198 and RE-7 for my 20" x40mm with a 1:12 twist Bbl...

AA1680 is MIA everywhere I looked...Do you maybe have a list of powders that are usable for
the combo above ?

Thanks.

One of the original design ‘goals’ of the x40 was for it to run with a rifle-length gas system and standard weight rifle buffer and spring…partly due to others had tried with similar cartridges and couldn’t make it work, that and being told it couldn’t be done….and kinda being enamored with the A2 configuration was helpful prod to do it…that’s how the cartridge ended up being the length it is…the ‘proof of concept’ cartridge started around 37mm and kept creeping the shoulder forward until it had sufficient capacity to run in a 20” rifle-length system with a 125gr TNT…. 

I’m kind of a velocity nerd, and had plenty of other cartridges to run subs or SBR set-ups….so from the start it was just a natural progression of velocity over the 300-221 (300 Whisper) in super-sonic loads initially just for hunting….aside from the development barrels we made local the very first ‘dedicated’ 7.62x40 barrel ever made was by John Noveske using our tooling and laid out in a 20” medium contour 1:12 twist with a rifle-length gas system…. 

The rifle-length system can be ‘finicky’ on the .30 cal bore with any of the smaller intermediate cartridges….if it was easy, companies would have been using it for the last20 or  30 years, but a good indication of the cut-off capacity needed to make a 20” rifle-length system run on a .30 cal bore is the x39 Russian – where 20” rifle-length systems are common and run great.….things like pressure loss at the gas block or gas key can compound cartridge capacity….but I think we’ve come up with a few set-ups that are ‘all season’ reliable and offer the longest lock-time – it’s real smooth, easy on brass, some guys claim more accurate (mixed opinion for me), and in a fairly even comparison shows about 25fps more velocity (the extreme spread on powder can be that much, so it ain’t that big of a deal)…..

1680 is a great all-around powder in the x40….and runs like a train in a correctly set-up 20” rifle-length gas system….usually posting velocities over 2,600 fps with a 125 TNT….it can be finicky to things like gas loss, binding, etc….but again, if set-up correctly it runs fine…no special components, just attention to assembly….but very load specific…you ain’t gonna get away with powder puff loads or real light bullets….but, as mentioned earlier in this thread, one of the reasons I like the lighter monolithics is they seem to build pressure like a slightly heavier bullet and run in systems like this…..going from a 20” barrel to a 22” or 24” using 1680 and something like a 125 TNT, we’ve seen very little velocity increase, but the lingering signs of pressure seem to present more than in the 20”, so to me that’s an indicator of 1680 flattening out or reaching its full potential in 20” barrels and needing to tune the powder/bullet combo a little more for 22 or 24”….depending on the bullet weight and composition, we’ve used 1680, 5744, 2200, 2015, 4198, and N133 in the 20” and longer rifle-length systems…. 

There are a couple things you can do mechanically to make a 20” rifle-length system run more consistent, and as you add length in front of the gas block like in the 22 or 24” it just gets easier and easier with each additional inch added to make the rifle-system run…

Thanks Kurt for your Input...I will try H4198 and RE-7  to see if it will run my 125 NBT's and my Hornady 140 BTHP's loads and through it in QL and Other Ballistic Programs.

DOOOHHH, I completely forgot that the Wilson x40 WT barrel is a 20" Bbl. with a Mid-Lenth gas system !