Reloading 7.62x39 for SKS question

[J Kelley]

I got a question hoping someone can provide an answer. I'm getting ready to reload, for the 1st time, 7.62x39 for my Romanian SKS with .311 bore. I will be using Sierra Pro Hunter 303 cal. .311" dia. 150gr Spitzer. Using H4895 [because I got about 16 pounds of the stuff]. Recommended COL = 2.220" HOWEVER I am using the original magazine well, not an aftermarket magazine so I can probably go longer than a 2.22 COL and still have the rifle reliable cycle without jamming. Using an empty cartridge with a bullet, the tip dyed with a Magic Marker, bullet started in the cartridge I placed the bullet in the chamber, end of casing was sticking out further than usual. I slowly closed the bolt until it was fully closed. I removed the bullet and could see when the lands seated against the bullet. Overall length of bullet against the lands measures 2.264". My thought is to try an overall length of 2.254 thinking I should be off the lands by 10 thousandths. Can someone experience with measuring the lands give their opinion on this? Do you think my 2.264 to lands is accurate? Is starting 10 thousands off the lands safe to prevent CUP overpressure? I eagerly wait to hear your opinions. Thanks.

 

[Blue68f100]

Since you closed the bolt on it it may actually be less that what you think. I prefer to use recommended AOL if I can, if not 0.025-0.030" of the lands. The best way is to push it in my hand not using the bolt. With your finger you should be able to know if you contacted the lands. If you did not tipping the barrel up the bullet should drop free on it's on. I adj the OAL after I find the best powder charge. Then I move in 0.005" increment both directions.

 

[Charliefrank]

Your on the right path. I used candle soot because it comes off easier. Now take the length that you have and shorten it by .005. Try it again. Keep doing this until there are no contact marks. I'm not entirely sure you'll increase accuracy in this type of rifle. I only do this for single shots and bolt actions that are used as single shots. Make sure your OAL remains the same through recoil and cycle. Also a longer AOL may not cycle properly.
One more note, if You change bullets you'll have to repeat the process over again for each bullet tried.

 

[FROGO207]

A shorter flat base bullet in the 123-125 grain weight will probably be more accurate in that rifle. Making a couple dummy rounds to try after settling on your OAL will help when trying them to see if they feed well. I could not get heavier boat tail bullets to shoot worth a hoot in either one of mine.Good luck!

 

[joneb]

Will a COL of 2.254" fit in the magazine and manually cycle? I think the max COL is around 2.2" for a SKS.

 

[Jesse Heywood]

I have been loading this bullet in my sino-soviet SKS. Worked out to a 2.190 OAL. Accuracy is very good, 5 shot groups covered b a quarter on an indoor 100 yd range. IIRC the OAL was determined by the magazine.

 

[J Kelley]

All, I appreciate the insight and advice. I decided to start with recommended COL. The other day it was a blistering warm sunny 37F so I got a chance to shoot the test loads with H4178 and H335. I have the H4895 loaded but have not yet shot, brrrrrr.........to cold now! The below pics show the results shooting from a Lead Sled on a rock solid no wiggle bench. The SKS had a trigger sear job done by a gunsmith in Georgia, can't remember which shop. The trigger is a little smoother but still not a 'target trigger'. Using a Redfield Revenge 4-plex 3-9x scope shooting at 100 yards. [you may have seen these photos in the other thread]



Interesting how the group tightened up near the same CUP with both powders. Instead of shooting up all of my Sierra Pro-Hunter 150gr that I used for 7.62x54, I will wait for some Sierra Pro-Hunter 125gr that I ordered from the local gun shop. And I like the candle soot idea, have not tried yet but I will.

 

[J Kelley]

Solid scope mount

 

[carbine85]

The SKS trigger is tricky to clean up. I've ruined 2 sears trying to perfect the triggers in these rifles. It's not easy to lighten, shorten the pull and get neutral engagement. A proper trigger job on these rifles goes a long way.
IMR4895 has always been my go to powder for 30 years but it's hard to find. I can always find H4895 so I guess I'll be switching over to that.

 

[J Kelley]

On the powder burn chart IMR 4895 is just a fuzz slower burning than H4895. I use H4895 in rifles for anything 30 cal or larger. I normally use Ramshot TAC in smaller than 30 cal. I found the paperwork on the SKS trigger job. After watching a youtube video made by one of their gunsmiths, I sent the trigger group to Moss Pawn and Gun - 6382 Old Dixie Hwy - Jonesboro, GA 30236 - 770.968.4949 they did a good job on the trigger, RCBS trigger pull scale measures pull at exactly 4 lbs 0 ounces. It still has a lot of travel before the trigger engages. When I got the trigger group back it needed a good cleaning because it had a lot of polishing compound in the nooks & crannies. I used paint thinner with cotton swabs and toothpicks to clean it.

 

[joneb]

I think I'd work the H4198 load up another grain.