Barnes 26gr Varmint Grenade

[BigMike]

Crazy these are the first loads of mine with benchmark I usually use varget for all my 32 and 40 loads. I was scratching my head on this one. I normally get flat primers with 28 of varget and 40 hornadys but ok head expansion. I was working this load up so I double checked (as always) my weights on the powder charge. I'm thinking the rem. 7.5 primers might be a little thinner than other primers? I remember seeing a comparison of primer thickness somewhere though, I would like to see that again if anybody has it. Now I was also using new Nosler brass that I have no experience with. But yeah I did find it strange that I showed pressure signs with a clean bore, new brass that was trimmed, and lighter bullets seated .015 off the lands...

[contender hunter]

Mike , Sounds like the 26 grenade might be a very accurate bullet !! I was a little skeptical just how accurate it would be , but things sound good . There is good primer info if you go to the home page and its the last heading under misc .Most are using either the rem. 7 1/2 and the CCI 450 or the BR-4 All three are the same cup thickness. Good luck with the grenades and good shooting !!!

[jo191145]

Big Mike

I saw your post yesterday and was surprised. I've pushed 40 Bergs past 27.0 with Benchmark and yes thats hot but I did not see any seriously dangerous pressure signs. My idea of seriously dangerous usually involves the loss of blood so please take that into consideration folks.

I'm not trying to discount your experience, just understand how it could be. When I got home from work today my Grenades were on the front step. I quickly loaded up a small Audette ladder in .03gn increments keeping in mind both your post and my own experience with BM.
Note: My tube was fouled with Win 748 from the prior days follies with the new Gun Haus bullets. Normally I would never mix powder fouling when trying to work a load but time was short and lots of rain in my future.

COL 2.265 (Gotta start somewhere and thats my lucky number)
I used CCI-450's cuz they were already primed. I really do not have much experience with that primer.

Started at 26.0gns after 3 foulers to help clean out the 748 = 4042fps
Skip a few loads to 26.9 = 4049 fps
27.2 = 4150 fps I would not doubt if the ball powder fouling was still skewing my velocitys at this point, possibly the whole test.
FWIW loads 26.3, 26.6, 26.9 grouped .258 at 200yds. Once again, not much faith in this test due to the alien powder fouling.
Pressure was nada zip zero at this point.

I concluded my test at 29.0gns with 4394fps. Loads 28.1, 28.4, 28.7 and 29.0 grouped .671 in a mostly horizontal pattern. (more realistic accuracy wise)
Still no sticky bolt or cratered primers but I could tell I'm getting up there. I also got no visible copper fouling which is odd for my gun using BM. I might just have to foul the barrel with 748 more often. 748 works quite nice by itself though.

I'm gonna clean the barrel and reshoot this test. I'll even load a touch higher than 29.0. Velocities and pressure are likely to climb using BM in a clean tube.

FWIW loads 27.2, 27.5 and 27.8 did not fall into any of the groups (nodes) They actually flew pretty wild compared to bullets my barrel will tolerate. They grouped 1.5 inches and were well to the left of the other two previously mentioned groups which are vertically aligned.

Folks, don't take any of my data as gospel. Start low and work up and keep it safe. At the velocities the 204 is capable of pushing this pill any coppering in the tube could accumulate extremely fast and heavy and really cause trouble quick.
I'm wondering if thats one of the possibilities for Mikes over pressure and high velocities.

Just a guess on my part but you P doggers are gonna like the down range results with this pill. My backstop behind the target board showed signs of immediate super explosive disintegration the likes I have not seen before.

A very preliminary thumbs up for the .204 grenades.

[BigMike]

Thanks everybody for the input so far!!! Thinking about what I did before the V.G. testing, I did shoot two foulers. They were berger moly's but like normal I clean between every 10 shots with kroil and butch's. That's the only thing I can say I did. I have never fouled with a moly bullet before so maybe that's the difference? What do you guys think

[K_Hini]

here you go big mike!!

http://www.jamescalhoon.com/primers_and_pressure.php

[jo191145]

Big Mike
I missed your 3rd post.

What gun/barrel are you shooting? (Custom or just lucky?)

To get the VG .015 off the lands you must have a short freebore.
I haven't miced them but they're roughly the size of a 35 Berger. They've long left the case before hitting the lands in any of the Savage tubes I've used. (I think)
I'll edit in my findings on that later.

What was your COL?

Close to the lands and new brass will both contribute to higher pressures.
Moly can be argued to death and everyone will have a different opinion.
Do you normally shoot moly Bergs in your gun or were these the first two?
Your post indicates these were the first two.
Dry bullet lubes are generally only a lubricant when both surfaces are coated with them. I've heard the argument that running naked pills with moly in the bore can result in excessive copper fouling. I've seen some evidence of this in the past when switching.
Theres plenty of shooters who mix back and forth with no consequences either.

I'm not sure if Butches and Kroil is a strong enough mix to thoroughly remove copper fouling. I get the feeling your a moly shooter as that mix is used very often for moly. If not you might want to upgrade to an effective copper cleaner.
If your getting a build up of copper/carbon/moly in the throat that can drastically raise pressures. The 22-250 and 6.5x284 are notorious for that.

Just goes to prove no two guns are alike and all loads need to be worked up.

Makes me wonder if these pills can be plated with bullet lubes or will the vibration affect the core? Anyone with info on that?

[BigMike]

jo191145 thanks for the help I appreciate it

Savage 12 FV factory other then bedding

C.O.L. is 2.374" .015" from lands

Nosler brass is ~1.833"

V.G. ~.6325"

I really like the Bergers, used to shoot moly exclusive but ran into probs. when shooting naked hornadys had too many flyers so I stopped shooting moly and flyers went away.

As far as copper and carbon I clean every 10 shots with Kroil and Butch's and when I get home I use Sweets to get the copper out, I just picked up some KG-12 too so we'll see how that works out. I had a 22-250AI that I LAUNCHED bullets out of, accurate but liked to become copper fouled, so I check for copper pretty regular.

Maybe I'll back it down a little and be happy with 4300 fps

[jo191145]

Short update

It seems Big Mike was correct. I can reach the lands with the 26 Grenade. Col is 2.397 touching the lands. That leaves .085 in the case.
Not a whole lot but doable.

I also reshot the BM ladder with a clean tube. As expected I got severe copper fouling. BM burns too clean for my gun at hyper velocities.
It works pretty well pushing the 40's slow.
Accuracy was not as good the on the second ladder. Velocities were consistent with the first ladder and the two nodes seemed to still be there.
I did note that the highest pressure did seem to be right around the 4400fps mark as Mike witnessed. With the large jump to the lands I employed it took me 29.0 gns to achieve that velocity.
Pressure actually seemed to decline as I foolishly went beyond that point. I entered the realm where the powder was no longer burning efficiently. Accuracy was totally non existant beyond that point.

I did learn these pills will hold together in flight no matter how fast you push them.

I'm wondering if an even faster burn rate might be in order. I'll try some of my more conventional sootier powders first tho.

[Rafter CT]

Well I went to the range today to try some 26 grain Varmint Grenades. I started out at 26.2 grs. of Benchmark and went up to 28 in 0.2 gr incriments. The best 5 shot group I got was 0.75 with 26.8 grs at 4220 fps. OAL was 2.295. I'd add a photo but don't know how. I guess that will work for squirells here in "Condor Country". Rifle is a Savage 12VF with a Bell Carlson Duramaxx stock glass bedded other than that just a stock Savage.

[Funbronco]

Has anyone loaded these with RE-10X ? I have had good luck with this powder pushing 39 BK and 35 Berg.

[Gube]

I just picked up two boxes of the V.G.'s from the local ma & pa shop.
I've got some benchmark, H-4895, and a whole lot of RL-10X to experiment with. I'm thinking that the burn rates might be to slow for these light wieights. I may have to go out and try a faster burning powder like H-4198 or maybe RL-7. Not sure when I can head out to do some testing. Gonna be busy until mid June. I'm very surprised that they are available out here in Canada already.

[tkv000]

I just picked up two boxes of the V.G.'s from the local ma & pa shop.
I've got some benchmark, H-4895, and a whole lot of RL-10X to experiment with. I'm thinking that the burn rates might be to slow for these light wieights. I may have to go out and try a faster burning powder like H-4198 or maybe RL-7. Not sure when I can head out to do some testing. Gonna be busy until mid June. I'm very surprised that they are available out here in Canada already.

Same, I went to my local reloading shop, and they had a pile of them! Which is unusual, usually in Canada I can wait up to a year before something new pops up.