Lets discuss reloading methods between bolt gun and semi autos.

[vigildom7]

Lets not discuss techniques used between the two(neck tension/ shoulder set back), but the actually firing method used.

I know some people prefer the optimal charge weight test.
Some prefer ladder tests.
While others like finding the velocity nodes/flat spots in a span of 10-20 different powder charges.

What affect can a gas system have on velocity and finding that velocity sweet spot?

I normally looking for a velocity node in my bolt gun reloading. Which tends to work reliably for everything I have done.

Never have actually tried getting a constant velocity load worked for a semi auto.

 

[nn8734]

Do the same speed node testing for your gas gun you have had success with that method in your bolt gun(s). There is no difference in approach (OCW, Ladder, other). You are still looking for the same few things:

1) Charge weight your min required velocity is achieved
2) Pressure threshold
3) optimal charge weight for stability whether you’re prioritizing speed (flat spots) or poi in adjacent charge weights

You will find that your pressure threshold is met earlier on the charge weight curve in a gas gun compared to a bolt gun in most cases (assuming exact same components are used and tested between the two).

Whatever you do, don’t over complicate it

 

[spife7980]

How do the development methods change? They dont.
You may want to add a couple thou more shoulder set back if you dont keep the dirty ass ars clean and a bit more neck tension if you have a way over gassed system etc... but I dont.

Can you push the semi autos as hard? No, they can still be pressurized when they start to unlock and you can get pressure signs at lower charges. Plus its just harder on the components as they move and slam about even more with over pressured rounds.


The only thing Ive noticed for development is that the last shot out of my ar15 can go different than the rest of the mag so I always load a dummy round last to keep pressure up on the carrier etc like it is for all of the prior shots.

 

[ma smith]

This is a good book, alot of people recommend it for general precision reloading guidance
FWIW it also covers alot of semi - auto vs bolt gun questions

Top-Grade Ammo a step by step guide to creating quality ammunition: Glen Zediker: 9781684192236: Amazon.com: Books

Top-Grade Ammo a step by step guide to creating quality ammunition [Glen Zediker] on Amazon.com. *FREE* shipping on qualifying offers. Top-Grade Ammo a step by step guide to creating quality ammunition

www.amazon.com

 

[Dogtown]

I just bump the shoulder back a bit more on gas gun ammo and use milspec primers.

 

[ReaperDriver]

The biggest lesson learned in reloading the same cartridge in a gas gun vs a bolt gun was to lower my velocity expectations. Shooting the same components, same bullet, etc. consistently hits really high pressure long before my bolt gun charge wts. I topped out in the gas gun at 100+ fps slower than my bolt gun and at more than a full grain less powder wt. My biggest mistake was to think that I should be able to achieve similar velocities as the bolt gun and I ruined a lot of expensive brass and burned through a lot of powder and bullets trying to chase that speed. So start waay lower than you think might need.