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Anybody know what the twist rate is in the barrels for these rifles ?
Thanks
Dean
Thanks
Dean
Twist rate for the 49/56 and 36 ?
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Thanks for the info Kelt ! Could someone translate the twist rate to non metric ? As in 1 in 12 etc .
Dean
Dean
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Merci Kelt ! So we are looking at a twist rate in the 49/56 of close to 1 in 11. The reason I ask is that I have been doing some research for bullets to get as close to the original 139 gr as possible. Hasnt been easy to do in 308 dia. Often times the bullets are described with a minimum twist rate recommended.
Dean
Dean
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Sierra makes a 135 gr matchking HPBT. Thats only 4 grs off. May experiment with them if I can find some loading data.
Dean
Dean
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The closest I can find is the 147gr FMJ bullet. It seems to work pretty well, but now I'm just trying to find a better powder. I've been trying to tweak my loads with H4895, but Im not getting the results I want. I'm gonna try IMR 4198 next, since it is a faster burning powder.
It's not so much the weight of the commonly-available .30 cal projectiles, as it is their length. The French Mil-spec 139 gr is very "skinny" and long compared to most .30 cal bullets of a similar weight. Although 15 grains heavier, the 150 gr M2 .30 cal FMJ's more closely replicate the length of the original military bullets. I've had good luck with them in my MAS 36 and 49/56.
The 147 gr FMJ's intended for 7.62x51 NATO would be OK, except that if you seat them to the crimping cannelure, they will be slightly short in OAL, leading to a big "jump" into the rifling upon firing. My results with the 147's have not been as good as the 150's.
JMc
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22,342 Posts
41 gr, 4895 IMR, 150 gr 308 FMJ
41 gr, 4895 IMR, 150 gr 308 FMJ
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Results: 3 shots under 1/4 inch group at 100 yds. Got the target to prove it. Now heres how I did it with a mint MAS out of the wax wrap. I pulled out the MAS firing pin spring and replaced with a M1 carbine spring cut to about a inch longer than the MAS original spring. I put two layers of cut 3/5 card material under the barrel chamber to float the barrel. I loaded the rounds to exact minimum specifications per the Hornady manual for 7.5 French. Each case was charged out of a digital powder measure/ scale (the RCBS COMBO Unit) to exactly 41 gr. of IMR 4895. I used pulled 150 gr LC bullets from Jeff Barlett in .308 caliber (30 cal. M2 actually). Each primer pocket carefully cleaned and Win Large rifle primers hand seated .
Email me you address/ mine is [email protected] and I will send you a picture of the target. 3 rounds touching at 100 yds.
I wrote about all this a few months ago on this forum and got a lot of steam from folks who doubted it. Well, guys: I did it and will welcome you to Quantico Virginia area anytime to let you take this rifle to the range. most welcome it.
I will digress and say this: the brass that I used was NOT MAS factory brass: it was 3006 CMP HXP brass run thru my Lee 7.5 resizing die and trimmed to proper lenght. It works extremely well in my rifle and the accuracy results are awesome.
41 gr, 4895 IMR, 150 gr 308 FMJ
--------------------------------------------------------------------------------
Results: 3 shots under 1/4 inch group at 100 yds. Got the target to prove it. Now heres how I did it with a mint MAS out of the wax wrap. I pulled out the MAS firing pin spring and replaced with a M1 carbine spring cut to about a inch longer than the MAS original spring. I put two layers of cut 3/5 card material under the barrel chamber to float the barrel. I loaded the rounds to exact minimum specifications per the Hornady manual for 7.5 French. Each case was charged out of a digital powder measure/ scale (the RCBS COMBO Unit) to exactly 41 gr. of IMR 4895. I used pulled 150 gr LC bullets from Jeff Barlett in .308 caliber (30 cal. M2 actually). Each primer pocket carefully cleaned and Win Large rifle primers hand seated .
Email me you address/ mine is [email protected] and I will send you a picture of the target. 3 rounds touching at 100 yds.
I wrote about all this a few months ago on this forum and got a lot of steam from folks who doubted it. Well, guys: I did it and will welcome you to Quantico Virginia area anytime to let you take this rifle to the range. most welcome it.
I will digress and say this: the brass that I used was NOT MAS factory brass: it was 3006 CMP HXP brass run thru my Lee 7.5 resizing die and trimmed to proper lenght. It works extremely well in my rifle and the accuracy results are awesome.
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