Seating .22/250 bullets long...pressure issues

[plinky]

Seating .22/250 bullets long...pressure issues.

Rifle is a Rem. 700 SPS Varmint. COAL is 2.533" when touching the lands. Hodgdon's COAL is 2.35" for most bullets. That would give the bullet nearly .200" jump to the lands. I've always seated out close the the rifling and never had a problem till now.

All loads use Hornady 50 gr V-Max and Win. brass (new at the first loading)

First load: CCI LR primer and 35.0gr Varget. COAL 2.5". Slight cratering around firing pin. No extrusion into extractor. Mixed grouping.

Second load: CCI LR BR primer and 36.0 Varget. COAL 2.51" Primer looks the same. No brass extrusion. Worse grouping. Stock is not fitting the action well. Change to Hogue pillar bedded stock.

Third load: WLR primer and 36.0 Varget. COAL 2.533" First shot blew the primer out of the case.

So apparently, seating out to the lands increased pressure like flipping a light switch. I don't think that the primer change would have a large effect as WLR is what Hodgdon used. And I worry that the first two loads had more pressure than what they looked like.

I'm hoping that others have loaded their .22/250 bullets long and can give an idea of where a safe maximum is. I'll stay .020 or .030" off the lands for now. How would you approach the problem?

 

[Afy]

Two ways to check this...

Drop the COAL to 2.513 and then try again at 2.523 also go back tot he BR primers.
Seating into the lands will increase pressure by 5K psi.

 

[Grumulkin]

When working up a load, groups start out large, tighten and, as pressure increases start to widen again. The difference between CCI LR and CCI BR2 primers is insignificant so I would say the "worse grouping" was due to increased pressure (i.e., pressure was probably on the ragged edge of being high). You then switched to WLR primers with the same load and in addition changed the seating depth. I would suspect the major factor in in the increased pressure, however, was not seating depth but the different primer.

1. It's OK to have the bullet almost touching the lands; I do that all the time including in a 22-250. It should not, however be actually touching the lands.

2. If you wish to use WLR primers, drop the load to no more than 34 gr. of Varget and work back up if you need to. When groups start widening, it's a sign of imminent excess pressure and there will be no accuracy gains or any other advantage to increasing the load further.

 

[243winxb]

Have you used these COL before with Varget? Or is this powder new to you? I would reduce powder charge. Check common things like case trim length, scale accuracy, neck diameter of the loaded rounds. 36.0gr of Varget just might be past your maximum load. If you look at Hodgdon site load data your will see that a 52gr HDY V-Max has a load maximum of 36.0 grs with Varget. You simply just have an OVER LOAD with the WLR primer. REduce the powder charge.

 

[plinky]

Thanks very much for your input fellows. You have helped me solidify my plan.

1. Stay off the lands by at least .020"
2. Reduce to 34.0 and work back up, more slowly.
3. Give CCI BR2s another try
4. Even with these changes, expect a lower max than what Hodgdon shows. I didn't think of it before but when priming after the second firing, some primers seemed a bit looser than normal. I chalked it up to the different primer. But it may indicate a very short case life even with my "safe" loads.

243winxb, I've used Varget a lot but this cartridge is new to me. The first post is my entire history with it. Seems like it's little more volatile than what I'm used to. And 1 grain jumps were probably a bit rash as well. Initially, I was going by Hodgdon's data for the 50 gr. Sierra which maxs at 37.5gr. Probably too much for the longer(?) V-Max. {edit}

BTW, does anyone have Hornady's data for Varget and the 50gr V-Max?

Again, you have my sincere appreciation.

 

[redneck2]

FWIW....I use Varget in my .223 with exceptional results. In my 22-250 Remmie, I use H-380 as it's slightly slower. I use 50 Nosler BT's in both. My 250 gives one hole groups at 100 yards.

Also...what brand of brass? I didn't see that. Remington had some runs of very soft brass. I have a friend that shoots high power. Remington would rip the heads off the cases in his AR. Switched to Win cases with the same load and it's run great ever since.

HTH

 

[243winxb]

BTW, 56 grains? Are you out to get me? LOL.

Hey Plinky, glad you caught that type O , i need a proof reader.

 

[plinky]

OK, being basicly lazy (too lazy to pull 19 bullets) and curious about the effect of seating depth, I seated the rest of the rounds .100" deeper and shot them this morning. Shot the first one "remote control". They actually looked alright pressure wise. About what you'd expect from a max load. Primers flattened but still with plenty of round edge and the extractor hole just beginning to make vague scrapings. If the first one had looked bad, I would not have shot any more.

Groups were consistantly a bit over an inch and the load is hotter than what I want to use on a steady basis. So I will start over with the plan outlined above.

Redneck, I'm using Winchester brass. That's also the brass that Hodgdon used so one more variable down.

My 250 gives one hole groups at 100 yards.

Yeah, rub it in! LOL

 

[Mal H]

plinky - I've got to add a bit to what's been said. The actions you stated in your first post would make me very nervous. You broke a very basic reloading rule - always back off a little (some say 10%) when you change any component.

You not only changed the primer, but you also seated the bullet out to a distance where you knew it would touch the lands.

Please rethink doing anything similar to that in the future, we want to keep you as a fully functional member.

 

[243winxb]

Seating into the lands will increase pressure by 5K psi.

Looks like AFY had the cause, the extra 5000 psi did it, if you were shooting the WLR loading.

 

[plinky]

Yes Mal H, This example of load devopement contains a number of lessons.

*Back off and work up again when changing any component.

*Touching the lands will usually increase pressure. Depending on the safety factor in the data, this could cause a failure.

*Using data for a same weight/different construction bullet may lead to pressure problems.

There are probably others. I hope I've learned my lesson.

Looks like AFY had the cause, the extra 5000 psi did it, if you were shooting the WLR loading.

Yes, it was the same ammo that blew yesterday, only seated .10" deeper

 

[rcmodel]

I would suggest you also check your case-neck thickness.

The 22-250 is one caliber I always had to neck-ream after a few loadings.

Try to fit a bullet back in the neck of a fired case.

If it won't go in easily, your case necks have thickened to the point they can't let go of the bullet in the chamber.

That will spike pressure right up there!

rc

 

[plinky]

Just checked that RC. The bullet is a light friction fit. As I understand it, the case in it's fired state has sprung back from the chamber walls maybe .002". So hopefully this is enough clearance.

I'll keep an eye on this and turn the necks if needed.

 

[K-Dirt]

BTW, does anyone have Hornady's data for Varget and the 50gr V-Max?

Hornady doesn't give max loads. They tell you how much of a certain powder will give you a certain velocity. Here's the loadings for Varget and the 50 gr v-max:

3300 fps = 31.8 gr.
3400 = 32.7
3500 = 33.7
3600 = 34.6
3700 = 35.5
3800 = 36.4

 

[dozernomore]

I to have recently purchased a rem sps varmint 22-250 heavy barrel,,and some reloading equiptment,,played a little with 52 grain hornady a-max,,just couldn't get them to stabilize,,playing with the 50 grain hornady V-max,,,C.O.L. 2.510,,and 36.8 grains of varget,,CCI Lr primers,winchester fire formed brass,,,,0.471 moa,,,my next batch gonna be,C.O.L. 2.513,,and 36.5.36.6,36.7 of varget,,ps I have noticed today at 36.8 grains,,they were all stabilized

 

[plinky]

Thanks for the data K-dirt. That seems to line up pretty close to the Hodgdon data for the 52gr. A-max.

dozernomore, nice shooting. Sounds like you have it worked out. That's a hot load though. I believe I'll drop back a grain or two. I was seeing a lot of potential at 35 gr. I think I went in the wrong direction from there.