Guys I am still trying to find a load that works for me in my new Kreighoff BBF.

I just got back from the range and noticed my brass has some bulges near the rim with some loads. It is about 1/4-3/8 long starting at the rim and moving forward. You can easily see it and feel it with your fingernail.

I do not get these bulges with S&B factory ammo.

Do you think this is a sign of too much pressure and I need to scrap the brass or do these guns have an unsupported portion of the chamber near the rim?

Thanks for your patience with me as I try to find the right load. I might just stick with the factory ammo and move on after today.

Powder is H100 and load is 48.5 grains. Maximum load for this powder with 162 hornady eld x is 51.1 per the hornady loading manual. 2585 FPS with magneto speed.

Next step is to try 150 grains bullets at 2600 FPS or just shoot factory 173 grain S&B.

Thanks again for all your help.

Your pressures are too high. I'd try 44gr of IMR 4831 with either bullet you're using. It should get you around 2,500 fps. It's just a fact or life with these guns that low pressure is necessary if you want to keep them together.

A 160gr pill at 2,375-2,450 fps is probably where you should be.

I have used a load of 43gr of IMR 4350 and 165 gr RN bullets that shot well in three different drillings of mine in 7X57R. Always work up and check accuracy, regulation to the sights, and signs of pressure.

I stop when I get good accuracy and regulation to the open sights.

Thank you that is what I expected.

Has anybody ever tried Norma factory 7x65R ammo in a combination gun?

I use Norma factory 7x65r in a Sauer drilling. I don't remember the load off the top of my head but it shoots to the sights and scope so I like it I was going to work up a load with a nosler but couldn't figure out why I would go to the trouble and then stuck with the Norma.

Matthew

What cartridge are we talking about ? 7x65R ?

Does the rifle have a jager block ?

If the cases are bulging immediately in front of the rim, the solid head is bulging, which would be a bit strange. If they are bulging at the end of, (ie at the muzzle end of) the solid head, it might be pressure, or it might simply be a loose chamber.They certainly do not, by design, have an unsupported area near the rim.

Published data for some of these rimmed cartridges is next to useless.

RWS and Norma factory ammo are both a couple of hundred FPS faster than the max you have quoted, and both makers market to non jager blocked BBFs

In a 7x65R a 160 at 2600, provided an appropriate powder is being used, is way, way softer than Euro factory ammo.

I load a 156 Oryx at 2650 in a BBF and a 160 NP at 2800 in a jager blocked Kipplauf. Both are 7x65R. The 156 load is very soft, which suits my purposes. The 160 is running at close to full potential but is not a hot load. Load details for both bear no resemblance to anything in a manual.

7x65r.

I looked at the gun last night and understand why it is bulging near the rim.

The bulge is right at the very edge of where the extractor holds the case when the gun is closed. When I say extractor, I mean the piece on the barrel that lifts the case out of the barrel when you break open the gun.

When the gun is closed, the part of the case closest to the rim is not inside the full chamber. It is supported by the ejector on the right side.

The bulge is right at the end of the extractor, where the extractor touches the chamber when the gun is closed.

It has to be over pressured because factory loads do not exhibit this bulge.

If the S&B factory stuff shoots accurately, I would stick with it. It’s good Ammo,I’ve used it in different Drillings for about 16 years. Not for use in long range hunting, but good out to 250.

Yes sir, too much of a good thing. Might oughta back off a bit.

By your pics it appears the extractor is sitting proud of the chamber wall. You don't have a bulge, what you have is an indent from the extractor. May need to relieve the extractor to match the chamber. Or if it fires and extracts OK leave it alone.

quote:

Originally posted by 243ackley:
Guys I am still trying to find a load that works for me in my new Kreighoff BBF.

I just got back from the range and noticed my brass has some bulges near the rim with some loads. It is about 1/4-3/8 long starting at the rim and moving forward. You can easily see it and feel it with your fingernail.

I do not get these bulges with S&B factory ammo.

Do you think this is a sign of too much pressure and I need to scrap the brass or do these guns have an unsupported portion of the chamber near the rim?

Thanks for your patience with me as I try to find the right load. I might just stick with the factory ammo and move on after today.

Powder is H100 and load is 48.5 grains. Maximum load for this powder with 162 hornady eld x is 51.1 per the hornady loading manual. 2585 FPS with magneto speed.

Next step is to try 150 grains bullets at 2600 FPS or just shoot factory 173 grain S&B.

Thanks again for all your help.

Hi, Well. I mentioned this in response to your previous post on sighting in a BBF. If you are going to reload a combination gun the first thing you need to do is try every brand of factory ammo you can to establish two things, the guns preferred bullet weight and velocity. This means choreographing each type and carefully noting accuracy and "climb" after the first shot.

If S&B 175gr factory gives you no problems then that's a good place to start.

First off, forget the loading manuals! This is especially true if you own a gun made by a different manufacturer than the loading manual used or the manual used a test barrel which is probably some type of bolt action pressure barrel (that may be 28 inches long!!) that is loaded to industry specs of pressure.

Next measure the COL and note the seating depth. Then remove the bullet, weigh the powder charge and note what type, ball or stick. Try to find out the make and type of powder, I found this to be easy with Norma ammo. It is also useful to measure the length of the factory bullet, especially if it is a round nosed bullet. Shorter or longer bullets with different shapes may have significant effects on accuracy and pressure.

It seemed comparing the weight of the charge in the factory ammo with the charges given in the Norma manual that the ammo was probably loaded with Norma 204. For my 7x57R I found Norma 204 was close to H-4350 which I had on hand. I had chronographed all my shots with Norma factory ammo so had a good average velocity to work from.

Now this is important, your results may differ as they say, go by the velocity that YOUR BBF delivers NOT what the ammo box says or what the manual says! I my case the velocity was higher than either the box or manual with the 156 gr loads and lower with any of the 175 gr loads I tried. Why? Probably different powders, bullet bearing surfaces, whatever, no matter, you are loading for YOUR BBF nothing else.

At this point slowly work up to the velocity that the factory load produced in your BBF. Anything strange happens before you reach the factory velocity you need to back off, maybe you guessed wrong on the powder or the bullets bearing surface is different from the factory bullet, check your seating depth, primers, whatever.

Once you have a good working load for your BBF stick with it, learn to shot that load. Virtually anything you come up with will work for deer sized game out to 250 to 300 yards. Elk? Well, the 154 gr Hornadys I shoot at 2650 killed a cow elk at 150 yards, however; it was a side on lung shot and the bullet didn't even hit a rib taking out both lungs, which proves not much...

Thanks for your thoughts. I have ordered a box of Norma 160 grain rounds and will shoot the this weekend.

You are correct about the velocities. I am using a magneto speed and a pact crony to verify what I am dealing with.

My friend in Germany who is a gunsmith told me any factory 7-65R ammo should be safe in a gun like mine.

quote:

Originally posted by 243ackley:
7x65r.

I looked at the gun last night and understand why it is bulging near the rim.

The bulge is right at the very edge of where the extractor holds the case when the gun is closed. When I say extractor, I mean the piece on the barrel that lifts the case out of the barrel when you break open the gun.

When the gun is closed, the part of the case closest to the rim is not inside the full chamber. It is supported by the ejector on the right side.

The bulge is right at the end of the extractor, where the extractor touches the chamber when the gun is closed.

It has to be over pressured because factory loads do not exhibit this bulge.

You found it! The pressure is too high, as you say. These combination and double rifles will not tolerate over pressure and will damage the piece in many cases with only one over pressure firing.

Good that you found it early!

…………………………………………………………………………………….

I tried the 160 grain norma 160 grain tip strike today and the velocity out of my gun was within 15 feet of the numbers on the box. The 2nd shot was 3 inches high at 100.

160 grain tipstrike at 2785.

No bulges.

Shot a doe at 265 yards today so I have found my solution. Norma factory ammo is what works.

Thank you very much for all of your help. I really appreciate you sharing your knowledge with me.

You are right about at 280 Rem. ballistics which is what I expect from this cartridge.

.

243ackley, we shoot a lot of 7x65R here in Germany (my wife has 2 KLB in 7x65R). Have shot Norma, S&B, RWS, Sako and others. Currently shooting RWS but never had any problems at all with any of the factory ammo. Good luck with the Norma. Its a great alround caliber!

.

Thanks. I got 5 boxes in the mail today so I am set for a while

Is that just a mark on the Case or can you feel a real bulge / ring. From the photos looks more cosmetic than harmful. Can you feel a fault on inside of the case - use a wee hook bent on end of paperclip. In mine I get a faint line.

I would suspect the extractor is not sitting perfectly flat - there may well be some crud - remove, give it a good clean and reassemble.

I too use a 7x65r - 50gn of Imr 4350 under a 173gn H-Mantle and 51.5gn of imr4831 under a 139gn soft point are my go to loads.

Just looking at the pictures id say the extractor is not the problem, what you have is a bad chamber, its oversize..Howeve I would suggest you take a chamber cast of both barrels before you do anything else, maybe return the gun..

If factory ammo shoots and does not leave a bulge, then drive on; you have no problem. Drillings are not guaranteed for hand loads. Neither is any other factory rifle.

I use 140 grains Accubond in my vierling, with 55,5 grains of Norma MRP. Muzzle velocity of 2700 fps. This is very light load. It has proven extremely precise in 3 drilling’s, with good terminal ballistics