Handloads for Sig Rattler

[dellet]

I use it with good results in supers and fired in the RARR. Compressed and a magnum primer took care of some the burn issues with supers with 140-160 gr bullets in the 10.5 inch pistol. I'm still working on which bullet/charge proves acceptable overall. Subs really work fine, erratic numbers and dirty burn occurs, though less so with the heaviest I've used so far (240 gr Missouri coated). I'm still looking for the box of 265 Acme coated I bought...

Anything you can do to get the pressure up or burn time lengthened really helps. Max density, heavy bullet long barrel. I tried in a 24” barrel and it was reasonable.

I have also used it for 22 K hornet and 218 Bee and some other odd ball cartridges. It actually does well in the smaller bores, but again that’s higher pressure. It still makes the Hornet bark like bigger cartridge tho.

By the way, happy birthday TR.

[jakeAMP]

So I went to the range this morning with 20 rounds. Chrono’d every shot and the data was consistent with my report yesterday. Shot paper at 50 yards, not even a remote sign of keyholing, and I managed to get an inch and a half group with five shots. Out of the Rattler’s 5.5” barrel and an Eotech with no magnification, I’m calling this load a win.

So as far as the unburnt powder issue goes, I suspected that might be the case, like I couldn’t believe how much powder I packed into those cases to get just above 1000fps. But, I don’t know if it’s how the Rattler’s piston system is designed, but I’m not seeing any more junk flying back into the fire control group than normal, which is awesome. I assume you’re probably right about it flying out the end of the barrel though. Is that a cause for concern when using a suppressor, or is it just something to look for when cleaning?

I don’t have my suppressor yet, I’ll be getting an OSS QD 7.62 any day here as soon as the ATF decides to take a walk to their mailbox.

[dellet]

You might escape some of the blow back with the OSS, they are supposed to have less back pressure.

In general, suppressors capture and hold the muzzle blast. When the bolt opens that back pressure is allowed out the breech end as well.

As a rule, slower powders have less peak pressure and more muzzle pressure. That's what makes them loud and dirty. Smokeless powder needs pressure and time to burn. CFE is low pressure, you have an ultra short barrel, it can work, just nor optimal.

As an example I use N105 a lot. About 7.8 grains for a 208 ELD. It will burn 95%+ of the powder in a 6" barrel vs say 80% of the 15 grains burned using CFE. So N105 leaves behind about 1/2 grain vs 3 grains of CFE.

The N105 will have a peak pressure around 55,000 psi vs probably around 30,000 of the CFE, it might even be less. The CFE tho will have a much higher muzzle pressure, that's why it will have less issues cycling. The trade off is noise that the suppressor has to mitigate. Think about blowing up a balloon and popping it, the higher the pressure, the bigger to pop.

It's just a choice

[jakeAMP]

That’s really interesting, thanks for the info, yours is exactly the kind of experience I was hoping to run into here. I’d never heard of n105, I’ll have to give that a try on the next run. I know I was pretty unhappy with the inconsistency of the H110 in my particular gun, so any other options are definitely appreciated.

I know the other powder that a lot of folks like is the Accurate 1680, though it’s my understanding it’s very similar to the CFE, could be mistaken though.

[dellet]

I was actually kind of surprised the numbers looked so bad with the H110. It's generally a pretty good choice. A primer change might not hurt, I am a fan of magnum primers with that powder and generally use Remington 7 1/2. Seating the bullet deeper or more neck tension might also help.

N105 might be a poor choice for the piston set up. not sure about that. N110 would be similar to H110, but more bulk and that is always helpful with Subs. All the Vihtvouri powders burn very clean.

[offsidewing]

Thanks to dellet, N120 has ruined every other powder I used for heavy subs in ARs.

[jakeAMP]

Quick update, after I used up all of my CFE BLK, I had six bullets left. I charged them with 10.6gr of H110 and tried seating the bullets a little deeper, 2.10” instead of 2.23”. The numbers WERE a bit better, averaged about 1024, std dev of 35 or so, and the ES was roughly 100.

So, Dellet, seating the bullet a bit deeper per your advice definitely seemed to help, but I wanted to ask you, how deep can you seat these bullets without causing an over-pressure situation?

Also, shooting them back to back, damn the H110 is way more quiet.

[dellet]

Also, shooting them back to back, damn the H110 is way more quiet.

That’s my biggest complaint about a powder in theory “optimized for the cartridge”

First thing I would do is add powder, that’s always the best solution

Chasing good loads with subs is very frustrating. You won’t really have a pressure issue with that load before you have a velocity issue. You might load a few at the original 10.7 grains to have a better idea of true velocity change from seating depth change. Other wise what I do is seat deeper until the velocity is higher than I want, or the ES is acceptable. Then you start all over again tuning for accuracy.

Honestly that’s why most sub loads shoot like crap. It’s a lot of work to get MOA results, and people won’t do it. It’s common to hear something like “that’s a bench rest technique, I don’t need it”. When the truth of the matter is, all loading for bench rest is, is paying attention to detail. Nothing more, nothing less. If you can put together a sub load that is MOA at 200, you’re better than the average handloader.

You might sort your brass. Headstamp first. Military brass is further sorted by date code. Example LC 12 all in one batch.

Then you can sort by weight, volume, base to datum after sized, just depends on how critical you want to be.

When I look at your original string of 20, I don’t see an ES of 130, I see 3-4 loads 40 fps apart. So what I often do is number the cases and sort by velocity. Many times you can prove it’s the brass after a couple of loadings. Then if you go back and check weight, volume and external measurements you actually learn something. You see a heavy case has less volume and a measurable velocity difference.

Then before you get all wrapped up chasing numbers, shoot it at 50/100 yards. It might surprise you, then you can decide I’d you want to work it more. Acceptable at 50 might fall apart at 100, or maybe not until 200.

[jakeAMP]

Right on, thank you for the insight.

Just wanted to post a quick update, the alphabet boys delivered today and I took the Rattler with the can to the range. It’s not *awfully* loud, but I must say I’m excited to give the H110 another shot when I grab some more bullets. I’m almost tempted to pull some bullets from the loads I already pressed.... but I’m gonna be lazy and just wait to score some new ones.

The CFE suppressed does indeed still have a bit of a bark to it. On the upside, the OSS did indeed keep her clean!

[jakeAMP]

Hey guys, sorry for the delay, current events have drawn my attention to securing more ammo for my other weapons so it took me some time to get back around to this project.

I switched things up a bit and went with the 220gr Sierra HPBT MKs.

Here’s the initial data:

Bullet: Sierra 220gr HPBT Matchking

Case: Converted Lake City (Fancy Brass Co.)

Powder: H110

Charge: 10.8gr

Primer: Winchester Small Rifle

COAL: 2.213”

Avg Velocity (15 rounds): 1089 fps

Std Dev: 14 fps


Really happy with this load so far. No signs of keyholing, shot a five shot 2 inch group at 50 yards, and managed to smack the 200 yard gong a couple times. Out of the Rattler’s tiny barrel, I’ll take that. And it is significantly cleaner and less “blasty” than the CFE BLK (quieter, too), and I think the slightly longer bullet and the need for slightly more powder to push the additional 20 grains really closed up the void in the case and the results were far more consistent. At the end of the day I’m looking at $0.69 per round, $0.57 if I don’t let myself get lazy and reuse the cases.

I’ll continue to chronograph this load as I take range trips, and I’ll be saving for some defensive bullets along the way to start working up loads with.

Hope y’all are doing ok in these crazy times!