Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
Member Login

Posted: 7/1/2012 10:20:24 AM EDT
Hi,

I have found in my rifle (which is a Larue Stealth 18", .223 wylde, 1 in 8 twist), that it enjoys 24.5 gr. of Varget using 69 gr. SMK BTHP at 2.26" in LC brass and remington 7 1/2 primer. I average 2604 fps and get under 1 moa at 300yards.

I am trying the 77gr. SMK BTHP with 23.9 gr. Varget and OAL at 2.26" but I am hearing some crunching when seating the bullet with my Redding Competition seating die. I chronographed this at 2595 fps average.

With 24.3 grains of Varget it is obvious that crunching/compression is occurring but there are no pressure signs and get 2641 fps average. But I noticed that the redding competition die is seating a bit longer in the compressed loads. Is this normal? Should I stop at 23.9 grains of Varget when I started hearing compression?

I have read internet posts of people seating at 2.260" and under using 24.5 grains of Varget and even more, but I have a hard time believing it because you can't seat the 77 grain SMK without compression  at those numbers.

iAlso does seating with compressed loads hurt the redding die? Have any of you experienced the redding die seating longer as loads are compressed?



Link Posted: 7/1/2012 10:34:06 AM EDT
IMO, you should not compress your powder charges to the point where you hear crunching.  The crunching is likely cracking of the granules, altering the powder burn characteristics.  This is bad (not safe, not the right thing to do).

Many people use compressed charges of Varget.  IMO, this is bad.

When I was doing load development testing I did some compressed charges.  I had a hard time keeping tight uniformity of OAL, as the compressed powder would push the bullet back as the stress relaxed.  How much relaxation varied from cartridge-to-cartridge.

I have read many stories and even seen a few pictures of cracked Redding seating stems after using it to compress loads.  It was never designed to do this.  I have read that the Forster is preferred for this, as it is mechanically more robust.

You should really think about whether 2.260" is the proper OAL.  A cartridge that tips in the magazine could get jammed.  The length from the rim edge to the tip (slant height) should be smaller than the magazine length.
Link Posted: 7/1/2012 10:50:41 AM EDT
The load you are using is very common in high power.  

Your die is a lot stronger than the powder.  

Don't worry about crunching. The load is over book max, but there are bunches of people shooting much hotter loads.  All that matters is how it works and shoots in your gun.
Link Posted: 7/1/2012 1:45:09 PM EDT
When I used Varget I would get the crunch but no problems with pressure or accuracy but it didn't give me the speed I was looking for. I was dead stuck on using an extruded powder because in my mind and based on loading match ammo in .308 the extruded powders is where it's at. After being frustrated in my quest for a little more speed I decided to give a ball pwder a whirl. I searched high and low locally for  Tac but couldn't find any and AA2520 was the closest thing to it that I could get on a regular. I settled on 24.5 grains and I get an honest 2820 fps out of an 18 inch barrel. I can shoot this olad on the hottest days without problems and the accuracy is just as good my Varget loads! I can even go a little more hotter but I decided this is good enough. You may take a look at a ball powder...
Link Posted: 7/1/2012 7:19:51 PM EDT





Quoted:



Hi,





I have found in my rifle (which is a Larue Stealth 18", .223 wylde, 1 in 8 twist), that it enjoys 24.5 gr. of Varget using 69 gr. SMK BTHP at 2.26" in LC brass and remington 7 1/2 primer. I average 2604 fps and get under 1 moa at 300yards.





I am trying the 77gr. SMK BTHP with 23.9 gr. Varget and OAL at 2.26" but I am hearing some crunching when seating the bullet with my Redding Competition seating die. I chronographed this at 2595 fps average.





With 24.3 grains of Varget it is obvious that crunching/compression is occurring but there are no pressure signs and get 2641 fps average. But I noticed that the redding competition die is seating a bit longer in the compressed loads. Is this normal? Should I stop at 23.9 grains of Varget when I started hearing compression?





I have read internet posts of people seating at 2.260" and under using 24.5 grains of Varget and even more, but I have a hard time believing it because you can't seat the 77 grain SMK without compression  at those numbers.





iAlso does seating with compressed loads hurt the redding die? Have any of you experienced the redding die seating longer as loads are compressed?



I have also noticed as you increase your charge weight into compression, it takes additional turns of the seating die to achieve the same OAL.  

 






If you feel like experimenting, try IMR8208XBR with that bullet (ETA: 77SMK) .  I get 2650fps (24.1g) from a Stealth 16" barrel, and under MOA.  







And, I agree that the crunching is not an issue.  I've crunched the heck outta some Varget.

 
Link Posted: 7/1/2012 7:26:19 PM EDT
Ive been compressing Varget for  18yrs if not longer.

Ive loaded 68/75gr Hornady and 69/77gr SMks with no problem....none what so ever. nothings gonna happen to the die.

After I finished my load development chores on all 3 weights of projectiles and found there sweet spot with Varget and my 24" 1-8 tube, its been consistant and accurate.

Some...not everybody freaks when they hear the word compress,d load...some of them wanna pull a Dr. Phil on you....hell...the load manual advise,s you thats it is a compress,d load.
Link Posted: 7/2/2012 10:06:04 AM EDT
Sierra recommends no more than 23.9 gr of Varget for the 77 SMK at 2.260" OAL.

Hodgdon recommends no more than 23.7 gr of Varget for the 77 SMK at 2.260" OAL.


This is extracted directly from the Redding web site:

"Heavily compressed loads can create problems when seating bullets. Our Competition Seating Die is not a powder compression die. The excessive force required to seat a bullet on a compressed load can damage the die and may cause seating depth variations. Switching to a faster burning or ball powder may eliminate the need to excessively compress the powder charge."

I have seen several pictures of seating stems cracked by compressed loads (usually/always >24 gr of Varget).

I don't use and wouldn't recommend more than 24.0 gr of Varget but know many people use more (>24.5 gr).  The thing is, many times the heavier charges are with bullets seated longer which are intended to be single loaded.  <––  This is likely not what you are doing.  Be careful interpeting the data you are given.
Link Posted: 7/2/2012 10:31:54 AM EDT
There's a 600 yard hi-power range less than 30 miles north of Sierra's plant in Sedalia, Mo.

This range is home range for Sierra employees who have years experience competing and winning with Sierra bullets.

These same employees are Sierra ballastic techs who take questions as posed in OP.
Link Posted: 7/2/2012 11:42:51 AM EDT
Link Posted: 7/2/2012 12:12:27 PM EDT
A drop tube will help with larger loads and arrange the powder to be more compact. The drop tube dates back to large loads of black powder.
I made mine at work from aluminum aircraft tubing and flared both ends.

Note, the longer the tube the more compaction you will have.

http://www.cabelas.com/black-powder-cartridge-reloading-cabelas-drop-tube-1.shtml
Link Posted: 7/3/2012 4:50:11 PM EDT
Quoted:
A drop tube will help with larger loads and arrange the powder to be more compact. The drop tube dates back to large loads of black powder.
I made mine at work from aluminum aircraft tubing and flared both ends.

Note, the longer the tube the more compaction you will have.

http://www.cabelas.com/black-powder-cartridge-reloading-cabelas-drop-tube-1.shtml


bingo
Top Top