9mm Load Workup with 115 gr X-treme Bullet

[BB in Texas]

I am fairly new to the word of reloading, but have read and studied a ton and still feel like a total dummy. Gaining the knowledge needed is a daunting task and I am again seeking advice and input from you who are more experienced. This forum is absolutely awesome!

I've been loading 9mm using 115 gr Montana Gold FMJ bullets and 115 gr Midway Bi-Metal CB bullets. I had refined my loads to OAL of 1.130 - 1.135 and using 4.5 - 4.7 gr of W231 produced the best overall results in my Springfield Arms and Beretta pistols (3.3 - 4.8 in barrels). Using WIN cases and CCI 500 primers. (I have safely fired loads of 4.8 gr but overall prefer the performance at 4.7gr.)

All the pistols passed the plunk test with both the bullets listed above.

Having exhausted my supply of those bullets I loaded some 115 gr X-treme bullets to the same 1.135 OALand 4.7 gr W231, and fired a a few rounds in each Springfield Arms pistol. (Hellcat, XDM Compact, XDM OSP) I was very happy with the performance in each as cycling and extraction were excellent, recoil slightly lower than even some lighter loads, and I did not observe evidence any high pressure signs on inspection of the cases. Now I hate to admit this, but I DID NOT perform the plunk test after loading the X-treme bullet. (But have since learned that it's necessary for each different bullet due to differences in the ogive.)

Preparing to load more X-treme bullets, I prepared some dummy rounds and performed the plunk test, finding that all three of the Springfields FAILED the plunk test (although I could barely see with the naked eye that they were too high in the barrel). So I proceeded to determine the maximum and ideal OAL for the pistols for the X-treme bullets. Using the marker test I determined the bullets were contacting the rifling at the 1.135 OAL. Clearly, the ogive is very different from the other bullets I was using. Gradually reducing the OAL I settled on 1.125 that plunked properly and would reliably cycle through all pistols using the dummy rounds.

I still have some of the rounds loaded with 4.7 gr W231 at 1.135 OAL and am now wondering if seating them the additional .010 deeper will create a dangerous additional pressure or if I should pull the bullets and re-work the load. (And if re-working, how much to decrease the charge.)

It's frustrating that I can't find a published load for a comparable bullet and powder! Thanks in advance.

 

[AJC1]

I will not say yes or no in your situation but I have loaded 5.0 grains at 1.090 and they were just fine. These were hot and shot out of a glock rated for +p. My loads used rmr jacketed bullets and I'm not familiar with your bullet. If it were me I would determine which gun is the strongest and start there.

 

[jag22]

You are waaaaaay over thinking this. How are you determining that a .1 grain powder difference or a .01 difference in
length will matter? Why are you tying to get the max OAL? There are tons of variations you can come up with. Not trying to pick on you, just pick a load from a table and shoot away. Remember, considering all the different factors, you are the weakest link so pick one and practice, practice, practice.

 

[WeekendReloader]

I load Berry's 115gn plated (similar to xtreme 115gn plated) according to Hodgdon's loading data. 1.1" COAL. I use a middle charge of 4.5gn of Win231.

 

[lordpaxman]

First, welcome to THR!
Second, Hope you Texans are doing ok, us Yanks get news that you’re in a world of hurt due to the winter storms.

I still have some of the rounds loaded with 4.7 gr W231 at 1.135 OAL and am now wondering if seating them the additional .010 deeper will create a dangerous additional pressure or if I should pull the bullets and re-work the load. (And if re-working, how much to decrease the charge.)

The online data shows a shorter COL than 1.135 for a similar bullet so if it was me, I’d either:
Load some more at 4.5 and 1.125 and see how they did, if ok then reseat your 4.7 to 1.125. Or
Reseat a handful of the 4.7 to 1.125 and try them. My experience with 231 is it can be pushed and is well behaved, not like Titegroup.

It's frustrating that I can't find a published load for a comparable bullet and powder!

Don’t know what to tell you, other than get used to it. Most of my bullets aren’t listed, so you find the most similar one in published data and work up to it. It’s part of the process. As you work up loads for more bullets and powder you’ll gain more confidence in extrapolating published data for your loads. A chrono can help you see what load changes amount to velocity changes. Good luck.

 

[BB in Texas]

First, welcome to THR!
Second, Hope you Texans are doing ok, us Yanks get news that you’re in a world of hurt due to the winter storms.

thanks for your kind thoughts. We survived the rare February weather with no damage or other mishaps! (Some we’re not so lucky.)

appreciate your comment and advice.

 

[Charlie98]

You are waaaaaay over thinking this.

Actually, I don't think he is. 9mm is a high pressure round and small variations in bullet seating depth can make big changes on pressure, and particularly with a fast powder.

Don’t know what to tell you, other than get used to it. Most of my bullets aren’t listed, so you find the most similar one in published data and work up to it. It’s part of the process.

That. But you are doing the right thing... checking your rounds for proper function before going whole hog on the press. If a standard cartridge configuration doesn't work, you would need to reduce and rework with that particular bullet... and this is where notes come in handy, make sure you note what you are doing and why... for reference later.