Plated vs. HiTek coated bullets

[Soonerpesek]

I just received my first order from RMR.
220Gr .400" Plated RNFP- not made by RMR, he is just selling them.

www.rmrbullets.com/shop/bullets/pistol/40-10mm/40-220-grain-plated-round-nose-flat-point-bullets-seconds-new/

I have used these bullets from SNS with good results

www.snscasting.com/40-s-w-220-grain-flat-point-red-coated-1000ct/

Here are the lengths of the projectiles:
SNS HiTek coated = .742"
RMR plated = .687"

These are being used for 10mm subsonic loads, 8" barrel, suppressed.
My current load for the SNS is 4.6gr Alliant Sport Pistol seated to 1.250". (chronoed @ 952fps)
I would like to use the same die setup ( on a Dillon 550B) for both loadings.
That being stated, if I load without changing any die setup, the seated length of the RMR is 1.240", which still leaves more space in the case than the SNS. Both cartridges "ploink" in the barrel at the respective lengths.

Am I correct in my assumption that the RMR loaded round will be a safe starting point with the current powder charge and seated length of 1.240"....?

Thanks in advance of your replies...

 

[EricBu]

Is your goal same die set up to speed loading? Or as close to same performance between the two loads? If it's die setup, I do 10 of ea and shoot them over a chrony and see where you're at. If you can live with the difference (and it will probably be pretty close anyway) then run it. Personally, I've found that plated and hi-tek coated bullets are pretty close...not like comparing to jacketed. Honestly, if a hundredth of an inch makes a difference between safe and dangerous.......your loads are already so far off the rez that the seating difference is the least of your worries.

 

[Soonerpesek]

Not necessarily to speed up the process, speed doesn’t really make any difference to me. I just didn’t want to alter the setup as is. As you could probably tell by the stated chrono readings, the loads aren’t “off the rex” by any means. Maybe I should have clarified safe…. I didn’t think it would be over max, wondering if it could now be under min …?

Also not expecting same performance out of the different loadings, just an alternative option…

Thanks for the input.

 

[EricBu]

Not necessarily to speed up the process, speed doesn’t really make any difference to me. I just didn’t want to alter the setup as is. As you could probably tell by the stated chrono readings, the loads aren’t “off the rex” by any means. Maybe I should have clarified safe…. I didn’t think it would be over max, wondering if it could now be under min …?

Also not expecting same performance out of the different loadings, just an alternative option…

Thanks for the input.

I get that, I too like to minimize messing with dies once I get them right. In the great scheme of things that tiny deviation won't make any difference unless you are already walking the line, either min or max. If you shoot 10 of each with the same die set up, and they do what you want, I'd run it. I have done the exact same thing with other bullets. The one thing I'd also recommend you check, is shoot the softer one without your can and make sure you get full function in the gun. All in all though, those look like awesome sub rounds!

 

[Blue68f100]

The RMR plated will have lower velocity due to excess case volume. Should be fine to shoot as is. As weather you get the accuracy and performance is up to you.

You could always put a index mark on the seating die stem, then shorten the length till you match the velocity of the SNS. I have index marks on my dies where I use multiple bullets. Just makes it easy to reset the die back to default settings.

 

[Soonerpesek]

You could always put a index mark on the seating die stem, then shorten the length till you match the velocity of the SNS. I have index marks on my dies where I use multiple bullets.

Makes sense,
They are Dillon dies, so no adjustable stem, have to move the die to adjust depth. (not an issue, just wanting to keep the same setup).
I haven't done in-depth measuring yet, but I'm thinking if I seat the RMR deeper - I will be getting into the tapered part of the bullet. I may have to increase the charge a bit to match velocities.
I have a Redding micrometer seating die for a 45-70 setup that works well, may have to think about a micro seating die for 10mm.....

 

[WeekendReloader]

I would seat the RMR to a shorter OAL so that the seating depth is the same. Then use the same powder charge. The two bullets “should” be pretty close in performance. Of course, you’ll have to test a few to see if you’re satisfied with them.

 

[FROGO207]

The way I get around the constant adjusting of dies when changing bullets is to have multiple dies preset for a particular bullet. Theoretically the die will stay where you set it and be repeatable. Admitidly none of mine are Dillon though. The other option,the first one I used until I got more dies was to make a dummy round for each one to use to reset the length of bullet insertion.
Blue68f100 is correct, they will have different speeds as they have different hardness of materials that engrave the lands with different pressures.

 

[lordpaxman]

The newer Dillon seater dies make it easy to change the seating stem which would be the option if you create a stem specifically for the bullet and could make it set to the COL you’d need. Other than that it’s witness marks on the die and change the height. I prefer to have the same COL so I’d be doing a load workup for the new bullet, but given the original question, I would consider the RMR load as safe to start. Range report please?

 

[AJC1]

There is two ways to change the output and only seating is being discussed.... if you want those to stay locked, change the powder dispenser to meet your need for each lot.

 

[drband]

The other option,the first one I used until I got more dies was to make a dummy round for each one to use to reset the length of bullet insertion.

This seems the simplest, least expensive option. I also use this method.

 

[Soonerpesek]

There is two ways to change the output and only seating is being discussed.... if you want those to stay locked, change the powder dispenser to meet your need for each lot.

I may have to increase the charge a bit to match velocities.

It has been mentioned...


Hey..........I just noticed you changed your avitar....
Those are pretty - but the other pic was prettier.....

 

[rocirish]

A dummy round for each bullet makes die adjustment simple.

 

[Soonerpesek]

Range report please?

Was able to get to the range today, here is some results:

All fired from CMMG Banshee 8" barrel, suppressed, 10 shot strings

All Starline cases, CCI 300 LP primers, Alliant Sport Pistol powder, chrono set at 10' ish from the muzzle.

The plated bullets are NOT made by RMR, they are just selling them. ( I am going to refer to those as RMR ).

RMR 220gr P RNFP 4.5gr 4.7gr both seated @ 1.240" - don't think I could go much deeper as the mouth would be getting into the tapered part of the bullet.
AvgFPS 893 910
Spread 20 14

SNS 220gr L TCFP 4.5gr 4.7gr both seated @ 1.255"
AvgFPS 927 940
Spread 16 31

The only thing I changed on the die setup was the powder charge, both seating lengths are with the same setup, the stem must contact them at different points due to the shape variances.

Alliant data shows a start charge of 4.3 and a max of 4.7 with the coated bullets.
The 4.7 rounds didn't show any signs of pressure to the best of my knowledge - primers were not blown out or flattened, no discernable felt recoil, ect.....

WARNING ABOUT THE NEXT STATEMENT:

I may try to go to 4.8gr and 4.9gr with the plated RMR bullet to see if I could get the velocities to match closer with the SNS coated bullets

All-in-all I was pleased with the results, pretty quiet with the can, and not real dirty considering suppressed shooting is dirtier to begin with ( in my opinion )

Anyhoo, for what it's worth, those are my findings.....

Edit to add: when I typed it out the "graph" looked better, when I hit "post" this is what came out....!