SMP-842

[Caster]

Take a look at post #11 for my data using 77g Noslers, should be fairly close.

Richard, where did you get your powder? I wonder if there's a difference in Western Cannon and St. Marks Powder?

BTW, thank you for participating. Any information you share on this powder is VERY much appreciated.

[RichardS]

I bought mine at the Knoxville gun show a few months ago, it is labeled WC. I believe it was from DLM's table/booth.

[Caster]

Thanks! I will have to ask David about that.

[mikegideon]

Just had a quick chat with Dolomite. I'm going to jump on the bandwagon too. I'll holler at David and arrange a hook-up.

[tn hp]

SMP, as you probably know is an abbreviation for "military surplus powder". My guru has recommended a start load of 24gr. of 842 in commercial cases with .77 or .75 gr BTHP bullets, Winchester SRP or CCI BR primers. This load is for a 20 inch WOA Varmint/match barrel. Results pending, proceed with caution!

[tn hp]

SMP, as you probably know is an abbreviation for "military surplus powder". My guru has recommended a start load of 24gr. of 842 in commercial cases with .77 or .75 gr BTHP bullets, Winchester SRP or CCI BR primers. This load is for a 20 inch WOA Varmint/match barrel. Results pending, proceed with caution!

Oh yeah, "St. Marks" I reviewed my data, while refilling the coffee cup, sorry about that!

[Caster]

Yes, SMP stands for St. Marks and I would NOT start at 24g of SMP842 with a 75g or 77g bullet.

At only 20g from a 24 inch barrel I was averaging 2645fps with a 73g Amax. I think you will see blown primers at 24g and possibly even case flow if you go any higher.

Do what you like, but my results indicate that would be a bad idea for a starting place using such a heavy bullet.

[mikegideon]

Here's what I was able to gather...

SMP842 was developed to replace WC844 in the new lead free M855 rounds. WC844 is sold commercially by Hogdon as H335. Here's a snapshot from a St. Mark's presentation. I have quickload data on H335.

[Dolomite_supafly]

Now that makes more sense. Because SMP 842 is closer to H335 than CFE 223. It is still not the same though.

Dolomite

[mikegideon]

I figured it's not quite the same, since lead free bullets are going to eat more case volume.

EDIT: it would be nice to find out the charge weights for the old and new M855 rounds, even if you had to pull the bullets and measure them.

Edited June 23, 2012 by mikegideon

[Dolomite_supafly]

I just read the velocities on their brochure. I am pushing a 62 grain bullet to 3,070 out of a 16" gun using the SMP 842 without signs of pressure.

Dolomite

[mikegideon]

I just read the velocities on their brochure. I am pushing a 62 grain bullet to 3,070 out of a 16" gun using the SMP 842 without signs of pressure.

Dolomite

Charge weight?

BTW... I believe you can be over pressure with a .223 without showing any signs. I know that's all you have to go on, but. You have guys jamming long bullets with Max+ compressed charges, and still not seeing any flat primers.

Edited June 23, 2012 by mikegideon

[Caster]

Charge weight?

BTW... I believe you can be over pressure with a .223 without showing any signs. I know that's all you have to go on, but. You have guys jamming long bullets with Max+ compressed charges, and still not seeing any flat primers.

24.0g gives me 2,900fps in a 16" AR. IIRC Dolomite is a little over 25g

[Caster]

I seem to be stuck on 24.0g with everything 62g or less. So far everything has looked good, accuracy has been excellent and accuracy very good.

Edited June 24, 2012 by Caster

[mikegideon]

Until somebody proves me wrong, I'm blaming the consistency on the fact that it's ball powder, instead of extruded. That's one of the reasons I want to play. I would love to get a single digit velocity spread using my Chargemaster. Hell, Dolomite's getting it by dropping charges with the Lee BallSpewer.

[mikegideon]

I seem to be stuck on 24.0g with everything 62g or less. So far everything has looked good, accuracy has been excellent and consistency very good.

Got some full load data? Bullet brand/type, OAL, charge weight, velocity, and barrel length. Trying to get my arms around it in Quickload.

[Caster]

Okay, a little more professional about it this morning.

Rifle-CZ527, 24 inch barrel, 1/9 twist.

Load 1

*Rp case

*CCI SR primer

*SPM-842 - 24g hand weighed

*OAL - 2.235

*50g Midway dogtown soft point

Fired a 30 shot string and recorded each shot.

Highest velocity - 3336 FPS

Lowest velocity - 3158 fps

Average velocity was - 3270 fps

ALL 30 shots were inside a 2 inch circle at 50 yards with only 5 fliers [still inside the 2 inch circle mind you] so accuracy was VERY nice.

Load 2

*RP case

*CCI SR primer

*SMP-842 - 20g hand weighed

*OAL - 2.275

*73g Hornady Amax

30 shot string

Highest velocity - 2682 FPS

Lowest velocity - 2592 FPS

Average for all shots was 2645 fps

Accuracy was nothing short of bad aßß!!! All shots touching inside a 2 inch circle at 50 yards. I'm loving this load!!!!!!!!!!!! It was very consistent by my lowly standards.

From page one of this thread.

[Caster]

Got some full load data? Bullet brand/type, OAL, charge weight, velocity, and barrel length. Trying to get my arms around it in Quickload.

I would add that all my loads thus far are from a full length resize and NO crimp. I've been getting wider variations in my velocity than Dolomite. After discussing it with him, he feels that the crimp he is using is helping with his consistency. I'm going to put that theory to the test when I can get back on the chronograph by crimping one of my previous loads.

[mikegideon]

I just hollered at David. He's at the machine gun shoot on OK. We're gonna hook up at the first of the week.

[mikegideon]

I would add that all my loads thus far are from a full length resize and NO crimp. I've been getting wider variations in my velocity than Dolomite. After discussing it with him, he feels that the crimp he is using is helping with his consistency. I'm going to put that theory to the test when I can get back on the chronograph by crimping one of my previous loads.

Yep. We discussed crimp. Brass type, and how many times it's been fired will scott the numbers around a little. I'll probably start out with some new Winchester brass and some lighter bullets. May even dump some into Lapua brass with the Bergers.

[dlm37015]

i was able to get a few of thenew 855a1 rounds today

[mikegideon]

i was able to get a few of thenew 855a1 rounds today

I hope you can share a few with my powder order.

[Caster]

Okay, I just got back in. Dang it's hot out there!!!

I'm beginning to think my Chrony may be off kilter. I am certainly happy with all results as far as accuracy, cleanliness and all but I am NOT getting the consistency result Dolomite is getting. Personally I could care less because my groups look so good. At 50 yards I put over 120 rounds inside a 2 inch circle. All this I did inside an hour. The barrel was pretty dang warm.

Today I reshot my 73g Amax load. I also fired a 45g round nose FMJ of unknown origin, 50g Speer TNT hollow point and 50g Hornady Zmax. I have the cheapest chrono that midways sells and it does not calculate SD or anything. I have the formula for calculating it, but I'm not going to do it. Should anyone want to do it I will gladly send my individual shot results. Anyway, here's todays work, all loads use a CCI SR primer and an RP case. I also switched from 30 shot strings to 15 shot strings with 30 rounds of each load; Half crimped, half NOT crimped.

45g RN FMJ

842 = 24.0g

OAL=2.240

15 shot string with crimp_______________15 shot string with NO crimp

*Hi = 3835fps__________________________*Hi = 3730

*Low = 3485___________________________*Low= 3608

*Average = 3714_______________________*Average=3677

50 speer TNT

842=24.0g

OAL=2.200

15 shot/Crimped______________________15 shot NO crimp

*Hi=3589_____________________________*Hi=3554

*Low=3369___________________________*Low=3199

*Avg=3478____________________________*Avg=3432

50g Zombie Max

842=24.0g

OAL=2.260

15shot/crimp_________________________15shot NO crimp

*Hi=3600_____________________________*Hi=3629

*Low=3257___________________________*Low=3208

*Avg=3355____________________________*Avg=3360

73g Amax

842=20.0g

OAL=2.275

15shot/Crimp_______________________15shot/NO crimp

*Hi=2826____________________________*Hi=2871

*Low=2635__________________________*Low=2713

*Avg=2733___________________________*Avg=2775

Edited June 24, 2012 by Caster

[Caster]

I'm going to leave my results up for now, but after talking with Dolomite over the phone, we've pretty much come to the conclusion my Chronograph is so basically the work I have done thus far was a waste of time. It's just not possible to get the accuracy I am getting with the velocity variances my Chrony is showing.

You can't put 120 rounds inside a 2 inch circle if you're getting as much as 300fps difference.

[Dolomite_supafly]

Something else.

Check you SD and your ES, with SD being the king. These are more critical than the High or the Low. You could have a string where you have 25 shots that are within 10fps of each other then a single, crazy round can go a few 100 fps high or low. By just looking at the high and low only the numbers can be very deceiving.

I don't believe that is going to fix your issue at the moment.

Dolomite