Do i need to worry?

[FAQMAT]

Hi there! I have this receipe for 9mm for like 6years now and shot +-8k rounds of it. 5.0gr SR 4756 behind a CamPro 124gr RN plated bullet. It work well in my guns and is very accurate. I tried this load in 4 different G17 a G19, G34 and a beretta 92FS. It chamber well, shoot accurate and clean, it show no sign of exessive pressure and chronoed at average 1059fps (+-20fps). The bullet is seated is a bit long and will not chamber in a G19 lone wolf barrel but i read that they are a little tight, so...

I recently, purchase an HK USP9 and shot this load in it. It shoot very accurate and i noticed no significant difference in recoil vs my other 9mm, but the primer seams flattened when shot in this gun! Whiskey Tango Foxtrot!!

Do i need to worry?

 

[jrcarbine]

Hi there! I have this receipe for 9mm for like 6years now and shot +-8k rounds of it. 5.5gr SR 4756 behind a CamPro 124gr RN plated bullet. It work well in my guns and is very accurate. I tried this load in 4 different G17 a G19, G34 and a beretta 92FS. It chamber well, shoot accurate and clean, it show no sign of exessive pressure and chronoed at average 1059fps (+-20fps). The bullet is seated is a bit long and will not chamber in a G19 lone wolf barrel but i read that they are a little tight, so...

I recently, purchase an HK USP9 and shot this load in it. It shoot very accurate and i noticed no significant difference in recoil vs my other 9mm, but the primer seams flattened when shot in this gun! Whiskey Tango Foxtrot!!

Do i need to worry?

If you could get a picture of the brass, that would help to identify the issue.

 

[FAQMAT]

Will do when i get home. As well as a measure of the OAL.

 

[mmcintyre1220]

I cant confirm this is the reason but I know the usp typically has a pretty tight barrel usually right at .354 while others are usually .356. If you were near max with your loads before but had no signs of over pressure this could be the reason why .

 

[jrcarbine]

Have you tried factory ammo in your USP?

 

[FAQMAT]

Edited my firs post, my load is actually 5.0gr of 4756

 

[FAQMAT]

Have you tried factory ammo in your USP?

Factory ammo? I only shoot factory in my shotguns and surplus ammo in my russian rifles. All my other guns shoot exclusively reloaded ammunitions.

 

[Superbrad]

Hk strike a primer with authority...... I have a P30L and it does the same thing..... Even with factory.... They are mil spec guns...... There's nothing wrong with a solid primer strike.....

 

[Pr589]

I'd drop the load by half a grain and see if this changes how the primers look and also how far/where the brass gets thrown.

Different chamber, different barrel can make a difference.

Although I too look at primers for the typical pressure signs, I'm not sure that these are really telling me much. For example, I have used the same small rifle primers in both my 223 and in my 9 mm. I see no flattening in either however one has chamber pressures of about 55,000 psi while the other is at 35,000 psi. If primers were responding to pressure, I'd think that there would be massive differences in primer flow.

 

[dirtybarry]

I've given up on trying to determine an over pressure condition based on primer appearance alone. If the brass ejects properly and the primers are still tight when de-capping then so what? If it was an 80 year old Luger that would be one thing but in a modern quality gun? I wouldn't lose any sleep.

 

[Ganderite]

Looks ok to me.

With a new gun I load a survey of, say, 4.0, 4.3, 4.6 & 4.9 and see if it shoot noticeably better with one load. Often it does.

 

[FAQMAT]

Thanks for your inputs guys. I handload for 10 different calibers for more than 10 years now, but it doesn't mean that i know everything yet. Better be on the safe side.

 

[BCRider]

Hodgdon's web site doesn't list the Campro but it does have information for a hollow back plated Berry 124. Also going by the information on the Berry's Bullets website we can look at the information for cast lead as well. And there's a load for a 125 cast lead bullet.

By the standards for the HBRN Berry your load is right in the middle of the range. But that's a hollow backed bullet and may have some other things going on for pressure.

There's a load for a 125 LCN that lists 4.8 as max.

But here again there's no actual Campro. But from these two loads it would seem like you might be near the top of the range.

Is the HK brand new? If it is the barrel might be rather tight and that's holding the bullet back with a bit more force which is then being reflected back to the casing and primer. As the barrel burnishes in over the first few hundred rounds it might stop doing this.

I'm also with Ganderite in thinking that while the primers are being punched pretty hard that they still aren't swaging out and filling the primer pockets fully. So while the pictures are showing primers that are seeing a high pressure I don't think it's overly high for a 9mm. That's a pretty punchy round at anywhere near full power by any standard. 9mm pressures being up in the range of some of the more solid .357magnum pressure readings after all. So a little flattening of the primers is sort of to be expected. As long as the edges don't fully square up I'm not sure I'd lose any sleep. And from what I'm seeing that isn't the case.

One thing for sure though. I'd say it's a stout enough load that you won't have ANY issues with meeting the ISPC power factor if that's a concern. So there might be SOME room to load down a little and still keep the guns cycling well. On the other hand if it's a really nice accuracy round reducing the power a hair might affect that.