160 gr .312 bullets?

[DresserDan]

I found some 160 gr plain base 5 groove bullets to reload in my 303 and 7.62R The overall on the lullet is .925 What should my oal for the 303 and the 7.62R be?I have not been able to find any info on this bullet 160gr 5 goove plain base .925length

[Ricochet]

You need to determine the proper OAL for yourself. Take a rod that will go from the muzzle to the breech face. Insert it all the way and mark it at the muzzle with a bit of electrical tape. Insert a bullet from the breech till the rifling stops it. You may gently wedge it there, or better, hold it in place with a rod from behind. Insert the other rod from the muzzle again till it stops touching the nose of the bullet. Mark it again with tape. The distance from the first mark to the second is the overall length of the cartridge that puts the bullet firmly against the rifling. A little bit less than that is a good starting point, if it will feed properly and if the bullet's seated deeply enough in the case to be securely held.

[DresserDan]

Thanks The bullet is so short that if loaded to the shortest oal listed amy where it will still most of the grooves outside the case.Will that be ok?

[Ricochet]

If there's enough of the boolit inside the case neck to hold it securely, no problem. Many of us often load with grooves outside the case. But if they're filled with sticky lube, keep them clean. Don't drop a round in the dirt and load it. Carrying them loose in a pocket could get messy, but no problem if they're kept in a box till loading in the gun. Not every groove always needs to be filled, of course, and that's something best determined by experiment. Oh, and cartridge overall lengths published for jacketed bullets are often longer than practical for many cast bullet designs. The most important thing is what I mentioned above, how far from contact with the rifling the boolit is.

[35 Whelen]

You need to determine the proper OAL for yourself. Take a rod that will go from the muzzle to the breech face. Insert it all the way and mark it at the muzzle with a bit of electrical tape. Insert a bullet from the breech till the rifling stops it. You may gently wedge it there, or better, hold it in place with a rod from behind. Insert the other rod from the muzzle again till it stops touching the nose of the bullet. Mark it again with tape. The distance from the first mark to the second is the overall length of the cartridge that puts the bullet firmly against the rifling. A little bit less than that is a good starting point, if it will feed properly and if the bullet's seated deeply enough in the case to be securely held.

Doc, you are a genius! I pull my hair out trying to determine proper overall lengths, but now it's easy! Today, my new Lyman 311672 mould came in and I used your method to determine the O.A.L. with that bullet in both my K-31's and my 03A3. Worked like a champ!


35W
P.S.- When are you gonna shave that thing?!?!?

[Ricochet]

When I get tired of it.

[missionary5155]

Good morning
Another simple OAL method is to neck size a fired case about 1/8 inch... enough to fairly well grip a cast boolit. (Check first to be sure the fired case will rechamber in rifle.) Fit the cast boolit in the neck well extended. Gently chamber the round and slowly close the bolt. You should be able to "Feel" the boolit bump into the rifling and get pushed further into the case. After bolt is completly closed reopen the bolt slowly and extract the case. Cast Boolit should be still in case at the MAX OAL. You should be able to see marks where the boolit "touched" the rifling. Measure and subtract the rifling engagement . With this measurement verify this OAL will function through rifle.
I have been doing this for years and gets you in the ball park. Most my cast boolits I seat to "Bump" into the rifle. (if they function through the rifle).
God Bless you Mike

[Larry Gibson]

Quite frankly with 160 gr PB bullets I wouldn't worry about AOL at all. I'd just load them so the bullet was not below the case neck. I'd also load them over 6 or 6.5 gr of Bullseye with no wad, filler or any thing else but powder in the case. Velocity should be around 1100+ fps with very good accuracy.

Larry Gibson

[TAWILDCATT]

I have loaded since 1939 and never knew a bout OAL till I got on these web sites with the nit pickers.I always loaded to base of neck or length to fit mag.
short bullets in to hold.(never realy used them).I just started to use LEEs 312-160 tl.before I used lyman 311291.13 gr of red dot gets 1680fps with lyman.1" groups at 100 yrds.