.303 bullets in a 7.62x39

[Wm Cook]

I’m picking up a CZ 527 in 7.62x39 this fall and I tinker quite a bit with precision handloading and I would like your opinion on trying this Sierra Matchking .303 bullet (.311) in the CZ. CZ said their bore was .311. I havn't bought Quickload yet but if anyone has a version of it I'd appreciate expected velocity with such a heavy bullet in the little x39 case. Probably a dumb idea. I get a lot of them lately. Sierra also makes a ProHunter in 125 and 150 grain, both .311. I'd appreciate your thoughts. Thank, Bill.

 

[dolek]

How long is the Sierra bullet ? What is the twist of the CZ barrel ? Are you going to single feed ?

 

[Ggmac]

I’m picking up a CZ 527 in 7.62x39 this fall and I tinker quite a bit with precision handloading and I would like your opinion on trying this Sierra Matchking .303 bullet (.311) in the CZ. CZ said their bore was .311. I havn't bought Quickload yet but if anyone has a version of it I'd appreciate expected velocity with such a heavy bullet in the little x39 case. Probably a dumb idea. I get a lot of them lately. Sierra also makes a ProHunter in 125 and 150 grain, both .311. I'd appreciate your thoughts. Thank, Bill.

View attachment 1198853

Tula makes a 154 led nose bullet for the sks and ak , the 154 is exceptional in my bolt 762x39 . Its about 1/2 the groups Size attained with the 123 gr loading .

 

[Wm Cook]

Thanks for helping. The barrel twist rate is 1 in 9.5. Barrel length is 16.6. Here are the specs that I could find on the Sierra 174 grain.

 

[Wm Cook]

Sorry forgot to answer this one. It’ll be single shot fed. Gotta do a search for a single shot sled for the CZ. Bill.

 

[dolek]

Sorry forgot to answer this one. It’ll be single shot fed. Gotta do a search for a single shot sled for the CZ. Bill.

Very good,single shot opens up your seating depth options . Now your chamber dictates,not your magazine . Anything is possible, you may find a magic combo that shoots well . I am watching this with interest . Mine is a Ruger,but I am curious about heavier bullets also.

 

[2506]

Don't know how they will shoot in a 7.62x39 but those Sierra 174 MKs really shoot in my all my 7.62x54R rifles that have bores that slug at 310.5 to 311. I have a couple that the bores run 311.5 and the Hornady 174RN .312 diameter really shoots in them.
I have had really great accuracy in the 7.62x39 with the Hornady .310, 123 SP and a compressed load of H322 in my Yugo SKS's. I use a Lee Factory Crimp Die to put enough crimp on the bullet to secure it in the case. Has worked excellent on a couple 40ish yard shots on deer.

 

[Wm Cook]

This CZ that’s on order has a brother coming with it. The second rifle is a Ruger Mini 30. Kind of doubling up usage for dies, powder etc.

The on line load data from Hodgdon shows a variety of powders for 150 grain bullets here and one of them is H322.

If you have it, there’s a good read I Handloader #177 that has numerous loads for 150 to 200 grain shot out of an old Ruger bolt gun(s) back in the mid 90’s. Bill.

 

[Zero333]

I ran the #'s in Quickload...

18.5" barrel
174 gr .311" SMK

at 50,000 psi it shows capable of reaching 2,000-2,050 fps with H-335, imr 4198, RL-7, N-120

 

[Wm Cook]

Three of those 4 Powders are on the shelf so I’m gonna to give it a go. I’ll let you know how things go. Thanks much. Bill.

 

[Siko12]

Why don't you slug the barrel and make sure of the dimensions? I would want to know for sure and, in my opinion, refrain from .312" jacketed bullets in a .308" barrel (but that's just .002" extra of engagement, prolly no problems)..

 

[Bill K]

You should be able to work up a load or two with those bullets, as the bore diameter is correct and what CZ says works best in their rifles with the .311 bore.
Check with Bob's Sled for a single shot magazine for your CZ. Believe he can help you out, with one or making one for you.

 

[Wm Cook]

The rifle’s been on order for a month and not expected to be here until late September. I’ll slug it to find the bore but CZ was firm on the .311 number they gave me for what their barrels measure. The Sierra’s MatchKings .303 bullets that I want to shoot in the 7.62 CZ (that I mentioned at the beginning of the thread) is sold by Sierra as .311.

I’m optimistic about this. I’ve picked out a few powders that I have in bulk, and another few that I want to try. In bulk, for the 174 grain MK’s I’ll try:

• H335 ~ 24 grains expected 1,895 fps
• H322 ~ 23 grains and expected 1,800 fps
• 4198H ~ 20 grains and expected 1,760 fps
• 2200 Accurate ~ xx x,xxx

But I also enough 5744 and Benchmark to give them a go. I’ll be a fun handloading project with a lot of variables. And since I’ll be feeding them one at a time I’ll have a bunch of seating depth before the lands, touching the lands and up to jam depth that I can try.

The question unanswered is whether anyone shot and can they share their experiences shooting “.303” jacketed bullets in a 7.62. I’ve shot lots of cast in 7.62x54 but we size them to whatever we want.

I know I’m not the first to ask that. This is my first (jacketed) handloading for a 7.62 and the question came up pretty quick. Thanks for the help. Bill.

 

[Wm Cook]

I found the site for the Original Bob Sled so that’s on my to do list as well. Thanks for that tip.

It’s a lot of fun gathering the gear needed to put together such a project. A few years back we didn’t have the internet as a resource. Back in the 90’s we didn’t have the information sourcing we do today but we got by.

Does anyone remember The Benchrest Primer that was put out by Precision Shooting (Dave Brennan?). And we lived for the delivery of Handloader and Rifle magazine. I’m about 10 issues short of a complete set of them. I found all of the heavy cast loads data from that 1995 issue 117. But I digress.

Here and now I’ve got most every thing I need either bought and on the shelf (brass, Redding and Wilson dies, scope, rings, Picatinny rail etc.) or tracked down to the point that I can purchase them.

A big thanks for all of the guidance. Bill.


Bill.

 

[Kmahow2]

Old thread I know, but I have shot a few PPU 174gr 303 bullets out of my Tikka T3 TAC 308, they were not loaded to max & the cases/primers showed no pressure signs, but they were surprisingly accurate at 600yds. Not as good as my match grade reloads, but 1.5-2moa @ 600yds from very cheap bullets. I only had these as some friends do reenactment & I make dummy 303 rounds for them to use & sell to he public.