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TX, USA
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Posted: 8/13/2020 11:20:35 AM EDT
Just out of curiosity, who has measured the distance to the lands in their semi auto platforms? It would be helpful to know what caliber, barrel and bullet if anybody has.
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Posted: 8/13/2020 5:41:08 PM EDT
[#1]
Never have. Being limited to OAL from mags I never saw a reason to bother.
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Posted: 8/13/2020 6:48:49 PM EDT
[#2]
I don't chase the lands on any rifle.
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Posted: 8/13/2020 9:24:53 PM EDT
[#3]
While I measure that dimension for my bolt guns as part of load development, never have for my semis - don't even own a .223 case for my Hornady comparator.
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TX, USA
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Posted: 8/13/2020 10:20:02 PM EDT
[#4]
All expected replies. Just wondering who has.
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Posted: 8/13/2020 11:21:47 PM EDT
[#5]
I have...can't recall the values off hand but they were LONG in most that I looked at. Most folks just work with the mag length that they are stuck with and vary the rest of the factors to get a load that works well for them.
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TX, USA
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Posted: 8/13/2020 11:59:55 PM EDT
[#6]
This is what I've suspected. With the recent articles about seating depth from the precision rifle blog and listening to Scott Satterlee about seating depth on the modern sniper podcast, it's had me wondering about semi autos and how far the bullets have to jump bc of mag restrictions, which actually might be a plus for a bigger window of accuracy and stability.
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Posted: 8/14/2020 12:33:34 AM EDT
[#7]
In service rifle you single load the 600 yard stage, so i have measured my .223. I shoot Hornady 80gr ELD loaded .010 off the lands with an OAL of 2.490.
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Posted: 8/14/2020 8:50:49 AM EDT
[#8]
Quote HistoryOriginally Posted By Demphna2: This is what I've suspected. With the recent articles about seating depth from the precision rifle blog and listening to Scott Satterlee about seating depth on the modern sniper podcast, it's had me wondering about semi autos and how far the bullets have to jump bc of mag restrictions, which actually might be a plus for a bigger window of accuracy and stability. I don't know about it being a plus but it's something that is what it is unless you want to single load a semi auto. You always could get a smith to use a shorter freebore chambering and get you closer to the lands at mag length. |
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GA, USA
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Posted: 8/14/2020 10:33:20 AM EDT
[#9]
A plan for gas guns is to use bullets that are less OAL sensitive which is often a lower BC bullet for its weight class.
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TX, USA
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Posted: 8/14/2020 2:04:57 PM EDT
[#10]
Quote HistoryOriginally Posted By Rob01: I don't know about it being a plus but it's something that is what it is unless you want to single load a semi auto. You always could get a smith to use a shorter freebore chambering and get you closer to the lands at mag length. I found this entire series interesting. I haven't had any desire to load closer to the lands and was thinking if the data here is solid, which it seems to be, mag length restrictions might be beneficial. |
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TX, USA
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Posted: 8/14/2020 2:07:08 PM EDT
[#11]
Quote HistoryOriginally Posted By robpiat: A plan for gas guns is to use bullets that are less OAL sensitive which is often a lower BC bullet for its weight class. |
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Posted: 8/14/2020 2:42:49 PM EDT
[#12]
Quote HistoryOriginally Posted By Demphna2: https://precisionrifleblog.com/2020/04/28/bullet-jump-research-and-load-development-tips/ I found this entire series interesting. I haven't had any desire to load closer to the lands and was thinking if the data here is solid, which it seems to be, mag length restrictions might be beneficial. Yeah I know all about that article. And you are right the ELDs, like the AMAX before them, are not overly jump sensitive and do very well from factory lengths. I shoot both factory and load them at .020" off, in bolt guns, and they both shoot well. |
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Posted: 9/2/2020 8:14:24 PM EDT
[#13]
Quote HistoryOriginally Posted By SHD: In service rifle you single load the 600 yard stage, so i have measured my .223. I shoot Hornady 80gr ELD loaded .010 off the lands with an OAL of 2.490. If I may, custom barrel and chamber ? ... Off the shelf barrel , if so what brand ? |
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Posted: 9/2/2020 8:54:10 PM EDT
[Last Edit: SHD]
[#14]
Quote HistoryOriginally Posted By bfoosh06: If I may, custom barrel and chamber ? ... Off the shelf barrel , if so what brand ? Quote HistoryOriginally Posted By bfoosh06: Originally Posted By SHD: In service rifle you single load the 600 yard stage, so i have measured my .223. I shoot Hornady 80gr ELD loaded .010 off the lands with an OAL of 2.490. If I may, custom barrel and chamber ? ... Off the shelf barrel , if so what brand ? |
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Posted: 9/2/2020 8:58:32 PM EDT
[Last Edit: SHD]
[#15]
Quote HistoryOriginally Posted By bfoosh06: If I may, custom barrel and chamber ? ... Off the shelf barrel , if so what brand ? Quote HistoryOriginally Posted By bfoosh06: Originally Posted By SHD: In service rifle you single load the 600 yard stage, so i have measured my .223. I shoot Hornady 80gr ELD loaded .010 off the lands with an OAL of 2.490. If I may, custom barrel and chamber ? ... Off the shelf barrel , if so what brand ? Edit... the shilen will shoot as tight as I can aim repeated and shoot off a bag with a 4.5 service rifle power scope, so five shots in just over 1.1" at 100 yards. With a lead sled or such would be better, but I don't have access to one. The BA was 2" at best in a lucky string. |
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TX, USA
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Posted: 9/3/2020 8:06:44 AM EDT
[#16]
Quote HistoryOriginally Posted By SHD: It's a ballistic advantage premium series DMR, 223 wylde and it doesn't shoot well. I've had two expert rifle folks shoot it, and they couldn't get it to shoot well either. I knew something was amiss when the shots didn't go anywhere near where I called them. I switched to a shilen ratchet barrel at more than twice the price, and it holds better than I can. Anyway, I measured the same bullet setup, and the shilen barrel is .100 shorter to the lands. Yes, I'm disappointed about the BA, but the oal difference really shocked me. I'm going to rework the BA barrel in a new receiver with more care, but I have less than high expectations. I'm not banging on BA... extreme accuracy costs money, and service rifle comp requires the equipment be perfect. I tried to cheap out. Edit... the shilen will shoot as tight as I can aim repeated and shoot off a bag with a 4.5 service rifle power scope, so five shots in just over 1.1" at 100 yards. With a lead sled or such would be better, but I don't have access to one. The BA was 2" at best in a lucky string. |
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Posted: 9/3/2020 8:32:43 AM EDT
[Last Edit: SHD]
[#17]
Quote HistoryOriginally Posted By Demphna2: What ammo? |
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Posted: 9/3/2020 3:09:29 PM EDT
[#18]
In .223 Wylde chamber a 80 grain SMK will touch rifling around 2.470" depending on throat wear and who's .223 Wylde reamer was used. 5.56mm NATO chambers can be as long as 2.550" to touch rifling. The only reason to load this long is 80 +/- grain bullets for 600 yards or longer tournaments.
I load virtually everything else at 2.250" and and adjust powder charges to get small groups. |
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Posted: 9/3/2020 3:23:28 PM EDT
[#19]
The Holy Trinity of Accuracy is seating depth, neck tension, and charge weight/volume.
Gas guns can’t really play too much seating depth if they want to feed from a magazine, so that leaves charge weight and neck tension. |
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Posted: 9/3/2020 3:36:38 PM EDT
[#20]
Quote HistoryOriginally Posted By borderpatrol: In .223 Wylde chamber a 80 grain SMK will touch rifling around 2.470" depending on throat wear and who's .223 Wylde reamer was used. 5.56mm NATO chambers can be as long as 2.550" to touch rifling. The only reason to load this long is 80 +/- grain bullets for 600 yards or longer tournaments. I load virtually everything else at 2.250" and and adjust powder charges to get small groups. |
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TX, USA
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Posted: 9/3/2020 5:14:08 PM EDT
[#21]
Quote HistoryOriginally Posted By ziarifleman: The Holy Trinity of Accuracy is seating depth, neck tension, and charge weight/volume. Gas guns can't really play too much seating depth if they want to feed from a magazine, so that leaves charge weight and neck tension. |
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Posted: 9/6/2020 12:29:14 AM EDT
[#22]
I've done it for all the semi-auto's I've reloaded for just so I know where my max is, but if I recall correctly only one was less than max mag length and it's my 16" AA barreled Grendel with 129gr ABLR's.
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Posted: 9/6/2020 1:19:09 AM EDT
[Last Edit: HighpowerRifleBrony]
[#23]
Quote HistoryOriginally Posted By SHD: It's a ballistic advantage premium series DMR, 223 wylde and it doesn't shoot well. I've had two expert rifle folks shoot it, and they couldn't get it to shoot well either. I knew something was amiss when the shots didn't go anywhere near where I called them. I switched to a shilen ratchet barrel at more than twice the price, and it holds better than I can. Anyway, I measured the same bullet setup, and the shilen barrel is .100 shorter to the lands. Yes, I'm disappointed about the BA, but the oal difference really shocked me. I'm going to rework the BA barrel in a new receiver with more care, but I have less than high expectations. I'm not banging on BA... extreme accuracy costs money, and service rifle comp requires the equipment be perfect. I tried to cheap out. Edit... the shilen will shoot as tight as I can aim repeated and shoot off a bag with a 4.5 service rifle power scope, so five shots in just over 1.1" at 100 yards. With a lead sled or such would be better, but I don't have access to one. The BA was 2" at best in a lucky string. I'm curious how the twists measure. The 80gr ELD is a lot of bullet for a button rifled 1:8. |
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Posted: 9/6/2020 1:29:42 AM EDT
[#24]
Quote HistoryOriginally Posted By HighpowerRifleBrony: I'm curious how the twists measure. The 80gr ELD is a lot of bullet for a button rifled 1:8. |
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Posted: 9/9/2020 11:12:45 PM EDT
[#25]
Quote HistoryOriginally Posted By maxxmojo: I've done it for all the semi-auto's I've reloaded for just so I know where my max is, but if I recall correctly only one was less than max mag length and it's my 16" AA barreled Grendel with 129gr ABLR's. Whats your oal and load for ablrs if you don't mind my asking? |
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Posted: 9/10/2020 12:44:34 AM EDT
[#26]
Update. I rebuilt the upper on a new receiver with a trued face, different bolt and used sleeve retainer goop between the barrel and receiver. Shooting 75 gr hornady hpbt at magazine length oal with 24.5gr of varget and a 14x scope the ba barrel shoots 1" 10 shot groups, so something is up with the first go maybe. Maybe the barrel didn't like the 80gr... I'll have to do some more study. Point is more than just the barrel matters, and ba shouldn't be an automatic no go.
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USA
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Posted: 9/10/2020 9:13:22 AM EDT
[#27]
No point as you are limited to magazine length. You are chasing ghosts bud.
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Posted: 9/13/2020 2:52:49 PM EDT
[#28]
Quote HistoryOriginally Posted By bendigo78: Whats your oal and load for ablrs if you don't mind my asking? Most of my gun stuff is in storage at the moment, but I do have some of my notes here and it looks like 30gr of CFE223 at 1.648 BTO. I don't know the exact COAL but it fits in an E-lander Grendel mag. CCI 450 primers in Hornady brass. Looks like the 129gr ABLR is leaving the 16" barrel at 2365 fps. YMMV. |
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TX, USA
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Posted: 9/17/2020 4:14:30 PM EDT
[Last Edit: DevL]
[#29]
Loaded to 2.260" a 77 TMK is 0.001" off the lands with my 16".223 Bartlein custom.
77 SMKs are stuffed WAY into the lands at normal length. I found the barrel shot best with 77 TMK 0.005" to 0.010" off the lands and I didnt have to worry about variances in seating depth or bullet length causing the tips to touch the front of magazine. It shoots .4-.8 MOA typically. Factory .223 77 SMK stuffed over 10thou into the lands still shoots sub MOA and is perfectly reliable. Shoots 95% suppressed. |
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AZ, USA
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Posted: 9/24/2020 3:05:42 AM EDT
[#30]
Imo for 556 and 308, its not needed as much but it doesn't hurt to experiment with. Now for 224V, that shit needs to be tested off the lands (around 0.040+).
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Posted: 9/24/2020 10:33:31 AM EDT
[#31]
Quote HistoryOriginally Posted By SHD: It's a ballistic advantage premium series DMR, 223 wylde and it doesn't shoot well. I've had two expert rifle folks shoot it, and they couldn't get it to shoot well either. I knew something was amiss when the shots didn't go anywhere near where I called them. I switched to a shilen ratchet barrel at more than twice the price, and it holds better than I can. Anyway, I measured the same bullet setup, and the shilen barrel is .100 shorter to the lands. Yes, I'm disappointed about the BA, but the oal difference really shocked me. I'm going to rework the BA barrel in a new receiver with more care, but I have less than high expectations. I'm not banging on BA... extreme accuracy costs money, and service rifle comp requires the equipment be perfect. I tried to cheap out. Edit... the shilen will shoot as tight as I can aim repeated and shoot off a bag with a 4.5 service rifle power scope, so five shots in just over 1.1" at 100 yards. With a lead sled or such would be better, but I don't have access to one. The BA was 2" at best in a lucky string. Thank You. |
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Posted: 9/24/2020 10:42:27 AM EDT
[#32]
Quote HistoryOriginally Posted By ziarifleman: The Holy Trinity of Accuracy is seating depth, neck tension, and charge weight/volume. Gas guns can’t really play too much seating depth if they want to feed from a magazine, so that leaves charge weight and neck tension. Lot of truth here. I would like to add to the neck tension part.... annealing helps assure consistent neck tension on those over worked case necks. A consistent neck tension helps precision far more then quite a few new reloaders realize. I have seen annealing the case necks, "restore" the precision on a known load.... the work hardened brass case necks just needed a "tune up" from the annealing |
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Posted: 9/24/2020 11:03:11 AM EDT
[#33]
Quote HistoryOriginally Posted By bfoosh06: Lot of truth here. I would like to add to the neck tension part.... annealing helps assure consistent neck tension on those over worked case necks. A consistent neck tension helps precision far more then quite a few new reloaders realize. I have seen annealing the case necks, "restore" the precision on a known load.... the work hardened brass case necks just needed a "tune up" from the annealing Quote HistoryOriginally Posted By bfoosh06: Originally Posted By ziarifleman: The Holy Trinity of Accuracy is seating depth, neck tension, and charge weight/volume. Gas guns can’t really play too much seating depth if they want to feed from a magazine, so that leaves charge weight and neck tension. Lot of truth here. I would like to add to the neck tension part.... annealing helps assure consistent neck tension on those over worked case necks. A consistent neck tension helps precision far more then quite a few new reloaders realize. I have seen annealing the case necks, "restore" the precision on a known load.... the work hardened brass case necks just needed a "tune up" from the annealing Indeed, annealing is huge. |
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Posted: 2/21/2021 10:40:21 PM EDT
[#34]
Update if anyone is still watching this. I built a new upper with the BA barrel that I couldn't get to perform, but not in service rifle configuration. It's just a long barrel shooter now. With a Specwar 7.62 suppressor on it, it is exceptionally accurate. I guess it just needed a pound or so hung off the end to tame the harmonics. I enjoy shooting it with a different use.
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Posted: 2/22/2021 2:18:46 PM EDT
[Last Edit: SpeyRod]
[#35]
I record everything so I know what I am dealing with. I don’t always do anything with the data but I have it if I want to use it.
On my current rifle, 6.5 c UU, I am going to play with the bto numbers to see if I can find any more accuracy. I am not really sure I can shoot well enough to measure what may be gained but it is something to experiment with. FWIW, the LT magazines I have a surprising amount of space to work with so there may be opportunity there. The Pmags barely fit a 2.80” oal. Here is a representative sample measurements from my rifle. Don’t use these for your rifle. 130 AR Hybrid avg 2.237” ogl to lands = 2.842” oal 140 otm avg 2.247” ogl to lands= 2.810” oal 139 Scenar 2.272” ogl to lands= 2.845” oal 136 Scenar L 2.237” ogl to lands = 2.823” oal |
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Posted: 2/22/2021 7:53:10 PM EDT
[Last Edit: Molon]
[#36]
Hornady 75 grain BTHP Match (0.224")
 The lot of T1 projectiles used for these measurements have a nominal length of 0.988” and I load them to a nominal COAL of 2.245”. When fired from a Colt SOCOM barrel with a 5.56mm NATO chamber, this COAL will create a jump to the lands of 178 thousandths of an inch. When fired from a Larue Stealth barrel with a 223 Wylde chamber, this COAL will create a jump to the lands of 115 thousandths of an inch and when fired from a Krieger barrel with a 223 Remington chamber, this COAL will create a jump to the lands of 78 thousandths of an inch. The jump to the lands figures stated above where obtained using a Sinclair bullet seating depth gauge and a Forster 223 Remington 1.4636” head-space gauge. These figures are contingent upon a variety of variables, such as the particular chamber reamer that was used for your barrel, the number of rounds that have been fired through your barrel when the measurement is obtained, the particular lot of bullets used and whether you use a virgin case, a fired case, a resized case or a head-space gauge to obtain this measurement. When I bothered to measure the throat erosion of one of my Krieger barreled semi-automatic AR-15s, the erosion of the lands averaged 0.0046" per 100 rounds fired.  .... |
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Posted: 2/22/2021 11:57:43 PM EDT
[#37]
Possible to use a lead sled for longer than mag COAL for single loadings?
I can't shoot accurately to notice the difference but wondering if anybody tried it |
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Posted: 2/23/2021 12:04:16 AM EDT
[#38]
Quote HistoryOriginally Posted By craig24680: Possible to use a lead sled for longer than mag COAL for single loadings? I can't shoot accurately to notice the difference but wondering if anybody tried it The Bob Sled is very common in Highpower and National Match competition. |
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Posted: 2/23/2021 6:58:25 PM EDT
[#39]
This got me thinking. I have 300 139 Scenar’s to play with. So far they are averaging just under 1 moa, .993 iirc. I would like to see if I can fine tune them to at least .75 moa with my loading techniques. As I said above, the LT mags give me a lot of space to play with. So I loaded 5 rounds each from 2.262” ogive reducing .01” each step down to 2.222”, 25 rounds total. At 2.262 the bullet should be .01 off the lands. I will shoot an moa challenge target and see what the results are. FWIW, I still have .04” of space left in the magazine on the longest load.
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Posted: 2/24/2021 6:44:10 PM EDT
[#40]
Load data:
6.5 Creedmoor New Lapua small primer brass neck ironed REM 71/2 primer H4350 40.7 gr Lapua Scenar 139 gr Here are the results: (all length to ogive) 2.222 ogl .966” group 2.232 ogl 1.006” group 2.242 ogl .933” group 2.252 ogl .466” group 2.262 ogl .909” group I think I will load more of those 2.252” ogl and see if that was a lucky group.  Attached File Attached File |
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Posted: 2/28/2021 3:52:33 PM EDT
[#41]
Quote HistoryOriginally Posted By Rob01: Never have. Being limited to OAL from mags I never saw a reason to bother. Unless you intend to use your semi-auto as a single shot what's the point? You could track barrel erosion, but that's a different topic. Magazine fed rifles need magazine length ammo. |
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Posted: 2/28/2021 5:13:16 PM EDT
[#42]
Quote HistoryOriginally Posted By borderpatrol: Unless you intend to use your semi-auto as a single shot what's the point? You could track barrel erosion, but that's a different topic. Magazine fed rifles need magazine length ammo. I think it depends on the ammo and chamber. Iirc, some of the light 52-53gr ammo can get real close if not jammed into the lands at mag length with a variety of chambers. I usually check to ensure mag length won’t jam and then work back from there. For the longer bullets, the ogive is typically too far back from the top to cause an issue in anything short of a custom chamber at mag length. Also, for the 224Valkyrie, the sweet spot that many of us have found with the 80gr ELD’s is 25-45 thou. That bullet/cartridge combo just seems to work, so it’s worth measuring for some “finicky” combos. For large frames, I look to find a jump that is tolerant over several thousandths just to ensure I’m not chasing a load or seeing variation due to setback/lengthening due to cycling/chambering (I don’t crimp). I’m not specifically looking for a set jump though. |
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