Stabilize 80 grn SMK with a 1-9 twist barrel.

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bearhunter

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Ganderite was kind enough to suggest some powders and a velocity range needed to stabilize 80 grain SMK bullets from a 1-9 twist barrel.

My rifle is the Mossberg mini action in a heavy laminated stock, that came with a bipod and Barska scope.

The scope went first, then the bipod.

The rifle now wears a Shepherd tactical scope, with AO, that works the same way as the old tech ART scopes. It also has two different reticles. One in the first focal plane and one in the second. Makes it super easy to make two shot zeroes. One for point of impact and one for verification after making the reticle adjustments to point of impact.

I used BLC2 powder over CCI450 magnum primers to get 2950 fps with Berger 77gr ELD and SMK 80 gr bullets, in Lapua brass.

I needed to work up to 25.0 grains of BLC2 to achieve 2950fps and it turned out to be the the best load for my rifle. Sub MOA groups, out to 300 yards.


I tried two rifles with the same twist. The other rifle is a Ruger #1, with a Varmint contour factory barrel and a 1-9 twist. The distinguishing difference between the rifles is barrel length. This rifle has a 20 inch barrel. Looks to be factory buttt???

Anyway, this rifle wouldn't produce enough velocity, with the same load the Mossberg likes. So back to the safe it goes. Couldn't get more than 2750 fps out of it and that wasn't enough to induce the spin needed to stabilize the long for weight ELD bullets I want to shoot.

Shouldn't normally be that much difference in velocity between the barrels, but it just goes to show how different one barrel can be from another.


Thanx Ganderite, now I can shoot those 80 grn SMK and 77 grn Berger ELD bullets that were picked up cheap and have gathered dust on the shelf for at least two years.
 
If that's a.223, then 25.5gr/BL(C)-2 is max (Hodgdon's site) and the listed velocity is 2768fps.

To get anywhere near 2950fps, you would need to use Varget (2869fps) and H4895 (2825fps).

Lyman lists H4895 as the most accurate at 23.3gr and is a compressed load.

My 16 year old Sierra program list Varget as the most accurate powder at 24.4gr but at 2800fps, with a max of 25.3gr at 2900fps. This was shot in a Rem 600 with a barrel twist of 1:8.
 
I have a thread on my Savage 110 EP .223 here on CGN where I posted some load data with 80gr ELDm and various powder charges in two powders.
 
RePete said:
If that's a.223, then 25.5gr/BL(C)-2 is max (Hodgdon's site) and the listed velocity is 2768fps.

To get anywhere near 2950fps, you would need to use Varget (2869fps) and H4895 (2825fps).

Lyman lists H4895 as the most accurate at 23.3gr and is a compressed load.

My 16 year old Sierra program list Varget as the most accurate powder at 24.4gr but at 2800fps, with a max of 25.3gr at 2900fps. This was shot in a Rem 600 with a barrel twist of 1:8.
Click to expand...


Well, don't tell my magnetospeed that and please don't tell the bullets that, because they're all behaving like they should.

My Lyman manual lists the max load at 25.0 for BLC2 and lists the velocity at 2860 fps from a 24in bbl with 46k CUP. Well within the safety limits of my rifle.

Manuals are a guide and the information in them is often dictated by legal issues and the people printing the information covering their butts.

Not that I blame them one bit.

Great accuracy, no signs of pressure on the case or stiff bolt lift, makes me a happy camper.

Thanx for the info though, it really was appreciated.
 
6MT said:
I agree here. Use Varget or H4895. Here is my load info, but my barrel is a 1:8" twist.

Caliber: .223rem
Rifle brand: EM Precision
Rifle Model: Cadex R700
Custom built: Yes
Barrel length and twist: 26" 1:8" Benchmark
Projectile brand, model and weight: Berger VLD Match 80gr
Powder brand and weight: Varget 23.8gr
LOAD CONSIDERED HOT OR CLOSE TO MAX: No
Primers: CCI BR4
Coal: N/A (too long to mag feed)
Ogive length: 1.870" CBTO
Brass: Lapua
Brass trim length: 1.750"
Distance to lands: .010"
Velocity (average): 2915fps (30 shot Ave ES=8 SD=3.2)
Outside temperature: 24c
Wind and direction: N/A
Barometric pressure and other relevant data: 1124m ASL, 40% RH, 101.4KPA

A wonderful load to a kilometre (with little wind). Best grouping was 5.25" at 700m (5 shots). According to iSnipe, this load transitions at 1050m.
This is not a compressed load. Just an FYI load for reference.

Here's my load for the Varmint gun. It is for a 69gr bullet though, but using BLC-2 powder in a 1:9" twist.

Caliber: .223rem
Rifle brand: CZ
Rifle Model: 527 Varmint
Custom built: No
Barrel length and twist: 25" 1:9"
Projectile brand, model and weight: Sierra 69gr SMK
Powder brand and weight: BLC-2 26.6gr
LOAD CONSIDERED HOT OR CLOSE TO MAX: No
Primers: CCI BR4
Coal:2.273" (magazine fed)
Ogive length: 1.885" CBTO
Brass: Lapua
Brass trim length: 1.750"
Distance to lands: .010"
Velocity (average): 2974fps (20 shot Ave ES=14 SD=4.7)
Outside temperature: 25c
Wind and direction: N/A
Barometric pressure and other relevant data: 792m ASL, 42% RH, 100.8KPA

This is a Varmint load. Devastating to 300m. According to iSnipe, this load transitions at 800m.
Click to expand...

Thanx for this as well. I think I will stick to my load for this particular rifle. So it's on max???? Each rifle is an entity unto itself.

The Ruger No1 I used the same loads in was showing pressure signs with the first loads which were well below maximum.

I have appx 1200 ea of the 80 grn SMK and another 700 of the Berger ELD 77 grn.

I'm not looking for anything else but to be able to utilize what I have already in the safe. I also have a lot of BLC2 to use up before going to the afterlife. I can't take it with me.

Buckmastr, I agree, with what you say and I've had difficulty getting those bullets to stabilize around 2800 fps. Not only that, I've found that max loads seldom give the best accuracy.

I got my information for a starting point from Ganderite, who did some testing for Savage Arms back in the day to see which twist rate would stabilize similar bullets. He graciously took the time to go back into his records on those tests and passed on several powders to me that should be able to give me the velocity I need out of the 24 inch bbl on my Mossberg.

My magnetospeed tells me I'm averaging around 2950 fps from that rifle, which is great for me and at pressures that are well within the safety parameters of the rifle.

The Ruger #1 was a different game. It showed pressure signs, a stiff lever drop with the very first load, which was well under max.

Take a look at the burn rates. All of the powders you folks are extolling are very close to BLC2.
 
I went back to my powder data. The BLC2 I'm using is an equivalent surplus powder called X2924, used for commercial loading. It's not regular canister grade powder.

I got it appx 25 years ago, from Tom Higginson of Higginson Powders, now called Ammomart. My cost on 28 pounds was about $4 per pound, shipped.

Tom sent me an extra 7 pound container, bullets, cases, primers for different cartridges he wanted SAFE loads developed for, with this powder.

He compared my results with those from other shooter/reloaders he trusted and printed them up on newsprint handouts, he included with his powder shipments to his customers.

X2924 has a burn rate very close to W748, which is close to Varget, which wasn't available back when I got this powder.

I chose BLC2 data as a STARTING point for Tom to print in his handouts. The other reloaders agreed.

When I took the powder out of the Higginson packaging, which was a cardboard box, with a plastic bag full of powder, I put it into laundry detergent containers, which easily held around ten pounds of the powder. I put big yellow labels on the containers with big black BLC2 letters and a date.

I should have included this info, but to be honest, I forgot about it and I was in the habit of marking the containers with the safe equivalent powder for data purposes, in the off chance someone else got ahold of the powder.

I suspect this is the main reason my velocities are as high as they are.
 
Yes, I see. The thing is, your 1-7 twist barrel will easily stabilize the bullets I have to push hard in my 1-9 twist barrel.

I agree, your barrel's twist rate is much more conducive.
 
bearhunter said:
I went back to my powder data. The BLC2 I'm using is an equivalent surplus powder called X2924, used for commercial loading. It's not regular canister grade powder.

I got it appx 25 years ago, from Tom Higginson of Higginson Powders, now called Ammomart. My cost on 28 pounds was about $4 per pound, shipped.

Tom sent me an extra 7 pound container, bullets, cases, primers for different cartridges he wanted SAFE loads developed for, with this powder.

He compared my results with those from other shooter/reloaders he trusted and printed them up on newsprint handouts, he included with his powder shipments to his customers.

X2924 has a burn rate very close to W748, which is close to Varget, which wasn't available back when I got this powder.

I chose BLC2 data as a STARTING point for Tom to print in his handouts. The other reloaders agreed.

When I took the powder out of the Higginson packaging, which was a cardboard box, with a plastic bag full of powder, I put it into laundry detergent containers, which easily held around ten pounds of the powder. I put big yellow labels on the containers with big black BLC2 letters and a date.

I should have included this info, but to be honest, I forgot about it and I was in the habit of marking the containers with the safe equivalent powder for data purposes, in the off chance someone else got ahold of the powder.

I suspect this is the main reason my velocities are as high as they are.
Click to expand...

That is important info. The BL(C)-2 you are using isn't the same as the one today, hence the difference.
 
bearhunter said:
I went back to my powder data. The BLC2 I'm using is an equivalent surplus powder called X2924, used for commercial loading. It's not regular canister grade powder.

I got it appx 25 years ago, from Tom Higginson of Higginson Powders, now called Ammomart. My cost on 28 pounds was about $4 per pound, shipped.

Tom sent me an extra 7 pound container, bullets, cases, primers for different cartridges he wanted SAFE loads developed for, with this powder.

He compared my results with those from other shooter/reloaders he trusted and printed them up on newsprint handouts, he included with his powder shipments to his customers.

X2924 has a burn rate very close to W748, which is close to Varget, which wasn't available back when I got this powder.

I chose BLC2 data as a STARTING point for Tom to print in his handouts. The other reloaders agreed.

When I took the powder out of the Higginson packaging, which was a cardboard box, with a plastic bag full of powder, I put it into laundry detergent containers, which easily held around ten pounds of the powder. I put big yellow labels on the containers with big black BLC2 letters and a date.

I should have included this info, but to be honest, I forgot about it and I was in the habit of marking the containers with the safe equivalent powder for data purposes, in the off chance someone else got ahold of the powder.

I suspect this is the main reason my velocities are as high as they are.
Click to expand...


I still have some of that powder tucked away. Works well. - dan
 
brybenn said:
I have a 1 in 9 twist and cant stabilize 80gr bullets with its 16.5" length yet. I moved down to 69gr stmk but havent found an accurate load yet
Click to expand...


Likely because you can't get enough velocity out of that barrel to induce more spin on the heavier bullets.

My Ruger No1, with a 1-9 twist rate has the same problem.
 
adamg said:
I piped up because I felt my velocity data with 80gr bullets would be useful data.
Click to expand...

Your data was useful. The thing is, your 1-7 twist barrel will induce a much faster spin on the bullet at much lower velocities, which in turn will readily stabilize long bullets.

I would prefer a faster twist rate than I have and I could rebarrel to achieve it or just purchase another rifle with the desirable twist rate.

The thing is, if the rifle I have, with the components I have on hand shoots acceptably and it fits me well, I really don't want to go through the effort at this point in time.
 
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