Seating Depth for Lyman #429640 HP

[Boyscout]

The Lyman Cast Bullet Manual says to seat these at 1.610 OAL which puts the roll crimp into the bullet at the start of ogive. If I seat to the top of the crimp groove the round is 1.700 OAL and the roll crimp stays in the groove. The longer OAL works fine in a 44 Rem Mag Handi-rifle and a Ruger Super Blackhawk. Are there any issues with developing my loads using the crimp groove? Accuracy is good with both.

[kevmc]

LCBM says 1.610 (not 1.160), I've got fat fingers too.......
I put the crimp in the crimp groove.....OAL is about 1.7
Why they list 1.610, I don't know....

[Boyscout]

I corrected the fat fingers. The bullet is not up against the rifling so I assumed that excessive pressure would not be a result. I also wanted the crimp to be strong enough to use in a revolver without damagaging the bearing surfaces and burn Win 296 more efficiently in the Handi-Rifle. 22.5 gn Win 296 and CCI LPM shoot very well out of the rifle. 1.610 shot well also.

[ValorsMinion]

I ran into the same issue. I crimp in the groove. It works fine in my revolvers but wont feed from the magazine in my rossi 92 due to length. I got them up to the same 22.5gr of h110 without issues and did not take them higher as accuracy was good. It shoots accurately in my R92 too if I feed them single shot by hand.

[Shuz]

I load my 429640's to between 1.700 and 1.710 for both Smiths and Rugers.

[Boyscout]

I was suprised by the amount of bearing surface ahead of the crimp groove. I sized to .429 and there was a good portion of the 429640 ahead of the crimp groove that had been sized.

[williamwaco]

The Lyman Cast Bullet Manual says to seat these at 1.610 OAL which puts the roll crimp into the bullet at the start of ogive. If I seat to the top of the crimp groove the round is 1.700 OAL and the roll crimp stays in the groove. The longer OAL works fine in a 44 Rem Mag Handi-rifle and a Ruger Super Blackhawk. Are there any issues with developing my loads using the crimp groove? Accuracy is good with both.



The "correct" OAL is the OAL that "Works fine" in your rifle.

In some cases it may be different for each rifle.

In a revolver, the correct length is - if there is a crimp groove, use it - Especially in revolvers with heavy recoil.


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