Hot Loads?

[paleojack01]

I have been reloading for years and have settled on some specific loads. I am using Precision Delta 230 gr RN FMJ with 6.4 grains of Unique. I use the Hornady manual for my load data and that book lists 6.6 as a max load. I had assumed as long as I was below that max load figure I was in a safe, no hot, load range. From a "feel" standpoint, these don't appear to be as hot as standard defense ammo (not +P). I ask because one of my pistols developed cracks in the alloy frame. I don't want this to happen again after repair so I need to be sure I'm not abusing the pistol. As a related question, could a weak recoil spring aggravate the problem?

Thanks for your advice.

[niemi24s]

Q1: What size 1911?
Q2: Manufacturer?
Q3: Crack location?

[paleojack01]

I had not listed the specifics of the pistol as I was trying to get a generic idea about what constitutes a "hot load" with the powder and bullet I listed. The crack has been attributed to shooting "hot loads".

The pistol is an alloy frame Kimber Ultra Carry. The crack was on both sides of the frame at the junction of the dust cover and the part of the frame where the rails start, right above and behind the frame opening for the slide stop.

I don't want this to happen again so am looking for what a reasonable load would be with 230 gr RN FMJ using Unique with CCI 300 primers. I'm thinking about dropping back to 6.0 grains.

Thanks for any tips.

[Hawkmoon]

Does Hornady list load data for the Precision Delta 230 gr RN FMJ bullet, or are you using data for some other bullet and assuming it's the same for the Precision Delta bullet? If so, that's never a valid assumption.

Do you have chronograph data for your loads? How do your velocities compare with the Hornady listing for whatever bullet was used to develop the data you are following?

[paleojack01]

No chrono sadly. Just using Hornady data. PD doesn't supply data. Anyone else here us PD bullets?

[niemi24s]

• Online Hornady load data... https://press.hornady.com/assets/sit...istol-data.pdf ...indicates loads for Unique to be 6.3 grains starting and 7.9 grains maximum, but for their 230 grain XTP bullet.

• Loadbook booklet on hand indicates a Hornady maximum load of Unique to be 6.1 grains for both the 230 grain XTP and RN Hornady bullets.

• Loadbooks Alliant Powder data shows a maximum load of 6.0 grains of Unique for a 230 grain

• Lyman Pistol & Revolver handbook shows starting and maximum loads of Unique for a 230 grain TMJ to be 5.9 and 6.6 grains, respectively.

The max load range here is 6.0 to 7.9 grains of Unique, so were your loads too hot? Kinda sounds like it.

However, I vaguely recall a thread years ago that dealt with some peculiarity of Precision Delta bullets. Maybe there's some useful info in it for you.

[paleojack01]

Thanks for providing all this data. My 10th edition Hornady book list 6.6 gr as max load for 4 different 230 grain bullets: FP, HAP, RN, and XTP. But I think all those other sources of data are very helpful, especially if Alliant lists 6.0 as max.

A number of years ago I decided to "work up a load" starting at the minimum charge. That was using my Colt 70 series. Everything functioned fine. However, my range uses ballistic rubber bunkers with a ballistic rubber face sheet and these loads bounced off the rubber. After that I pushed my loads to the higher end. Looks like i overreached this time.

I'll do a search here for Precision Delta to see if I can find that thread you mentioned. One obvious difference between PD and Hornady is the surface finish. Hornady are smooth and shiny while PD had a dull, possibly, rougher surface.

[niemi24s]

I'll do a search here for Precision Delta to see if I can find that thread you mentioned.

That mention may have been a senior moment. Looked for it myself without any luck.

[Hawkmoon]

Thanks for providing all this data. My 10th edition Hornady book list 6.6 gr as max load for 4 different 230 grain bullets: FP, HAP, RN, and XTP. But I think all those other sources of data are very helpful, especially if Alliant lists 6.0 as max.

I notive that you have not answered my question, which was, "Does Hornady list load data for the Precision Delta 230 gr RN FMJ bullet, or are you using data for some other bullet and assuming it's the same for the Precision Delta bullet?"

Based on your posts since I asked that question, it appears that the answer is that you do NOT have load data for a Precision Delta bullet, that you are using data for other bullets and extrapolating. As I also said in the same post, "If so, that's never a valid assumption." Every bullet is different. Precision Delta bullets may be longer or shorter than whatever 230-grain FMJ you have a recipe for. They may be fatter. They may have a core that's harder or softer, and/or a jacket that's harder/softer/thinner/thicker. A Precision Delta bullet may behave exactly the same as whatever bullet is listed in the recipe -- but the odds are it won't.

Alliant's on-line load data includes one recipe for Unique with a bullet somewhat close to the Precision Delta 230-grain FMJ: it's for a Speer 230-grain TMJ. But "TMJ" is an acronym for "Total Metal Jacket," meaning the base of the bullet is covered. And that means it's not really a "jacket," it's a thick plating. The maximum for Unique with this bullet is 6.5 grains at a C.O.A.L. of 1.26 inches. I notice that you haven't mentioned what you used as your C.O.A.L. That's critical.

Of course, the shape of the bullet plays into this, too. Flat nose and hollow point bullets don't use the same C.O.A.L. as round nose bullets. But the key issue isn't the overall length -- that directly affects only whether or not the round will fit the magazine, and whether or not the round will chamber. But INDIRECTLY the C.O.A.L. affects the bullet's seating depth in the case, and the seating depth affects pressure. Take two 230-grain FMJ bullets. One is short and fat, the other is long and skinny. Load them both the the same C.O.A.L. and, obviously, the long, skinny one will extend deeper into the case, leaving less residual volume. That generates higher pressure.

[paleojack01]

You are correct. I wasn't very clear on that. Yes, I did make assumptions and am using the Hornady Manual as my guide. I haven't seen anyone offering any load data for PD bullets. I was hoping that might pop up here.

For a FMJ RN 230gr Hornady bullet, their manual shows 6.6 gr of Unique as a max load. This load is for all of their 230 gr FMJ bullets regardless of shape. They list COAL for the RN at 2.10. According to data on this site, the Hornady 230 gr RN FMJ is .007 shorter than my PD 230 gr RN FMJ. My COAL is 1.230 so I have more internal volume in the case which should reduce pressures (not considering other bullet differences like hardness).

The Alliant site also shows a jacketed gold dot 230 gr round with max load of 6.0 gr of Unique at 1.2 COAL.

It surprises me that Alliant would have a higher max load for a plated bullet. It is my understanding that plated bullets should be loaded as if they were lead bullets at lower velocities.