Setting overall length on a Double rifle

Andrew NOLA · Jul 7, 2026

I am new to reloading for double rifles.

I would appreciate advice from those who are already reloading for them.

I have a 470 NE, am waiting on a 500-416 shortly and will get a 450/400 in about 3 more months. I have a method that I use for bolt action rifles to set overall cartridge length, but realized I could use some guidance from those who are reloading for doubles.

Appreciate the help.

Schüler Jumbo · Jul 7, 2026

I use the Hornady Lock-N-Load OAL Gauge to determine bullet seating depth off lands for my double. Same as bolt gun.

MacJenkins · Jul 7, 2026

Most guys will load so you get a good crimp in the cannelure. We are not chasing the accuracy like in a blot gun. Good crimp is important in the heavy kickers so your bullet in the second barrel won’t start to come unseated after the first shot.

deewayne2003 · Jul 7, 2026

MacJenkins said:
Most guys will load so you get a good crimp in the cannelure. We are not chasing the accuracy like in a blot gun. Good crimp is important in the heavy kickers so your bullet in the second barrel won’t start to come unseated after the first shot.

I’ll add that I’ve found the custom ordered Lee FCD to be money well spent and switching from Hornady to CH4D dies made my .470 brass life extend dramatically.

Also graphite neck lube and imperial sizing wax has been a game changer as well.

farmer_john · Jul 7, 2026

Id start loading to spec. But if you want to know where lands are

Im a bit old school and this process would be different for a double. In a bolt gun strip the bolt and make a very very long dummy round and every time you try to close without effort reduce by a little bit till it does.
When the bolt handle closes with no effort your not pushing bullet into lands and your right at it. Thats basically your wiggle room from spec.
For a double id do the same load a dummy long. And gently try to close. When closes with no effort thats your max length from spec
My understanding of doubles is there regulated to a certian load. Id buy that measure oal and velocity and use that as my starting point
Then just reload it for cost and consistsncy.

Luvthunt · Jul 13, 2026

deewayne2003 said:
I’ll add that I’ve found the custom ordered Lee FCD to be money well spent and switching from Hornady to CH4D dies made my .470 brass life extend dramatically.

Also graphite neck lube and imperial sizing wax has been a game changer as well.

+1

dogcat1 · Jul 13, 2026

I am not an expert on setting the LOP or barrel length. Here is what I learned in sizing mine.

1. It handles like a SxS shotgun. They tend to have a longer LOP.
2. Get fitted by an expert. JJ Perideoux did me and I was pleased with what he set me up for.
3. Be sure to handle several. They all feel different and balance a little different. I found a couple that I liked but felt "clunky" when I mounted them.
4. Get help on fitting and selecting. You can get your pants pulled down on these as they are all different.

Good luck.

Setting overall length on a Double rifle

Andrew NOLA

Schüler Jumbo

MacJenkins

deewayne2003

farmer_john

Luvthunt

dogcat1

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