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Raptortrapper
Posts: 94 Member
10mm TRP

I have a new 10mm Springfield TRP with a 6" slide that I'm working with. Just ordered some 220gr FN-FB bullets from Rimrock. Same bullet that Buffalo Bore loads in their heavy 10mm stuff. Can't find any load data with this bullet as most manuals stop at 200gr jacketed bullets, but have an email in to Rimrock to see if they have suggested loads. Thought I'd throw it out here on the forum as well and see if any of you have used this bullet, and what powder / load you used with it. How did the bullet perform for you?
I also have some 180gr Speer Gold Dot bonded hollow point bullets coming as they were recommended by someone I have complete trust in as far as bullet choices go. Some of his *other* decisions may require someone to hold his beer, but he knows his bullets pretty well.
Found plenty of load data for these bullets, and expect to end up close to what I was using with 180gr XTP's. Loaded them with 9.5gr Longshot and am getting 1367fps. It was by far the most accurate load out of this 1911, so far.
I also have some 180gr Speer Gold Dot bonded hollow point bullets coming as they were recommended by someone I have complete trust in as far as bullet choices go. Some of his *other* decisions may require someone to hold his beer, but he knows his bullets pretty well.

Some people are like a slinky-- not much fun till you push them down the stairs!
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I like heavy for caliber, and when I saw those 220's, I just couldn't pass them up!
-- Johann Wolfgang von Goethe, German writer and politician
I will certainly be updating this thread as things move along in this endeavor. Information for the 220gr HC in a 10mm has been VERY hard to find, so hopefully the information in this thread will help someone down the road. That's what we're here for anyway, isn't it??!!
When I was running my 45 Colt, I had excellent results with 335gr. HC running anywhere between 900 and 1000 fps. Seeing the above velocities is very encouraging for this 220gr bullet in the 10mm. Granted, I also ran the 45 Colt pretty hard at times using some H110, but it wasn't "nessecary". Sure was fun though!!
Might have to tey them in my 10mm.
Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
I'd rather have my sister work in a whorehouse than own another Taurus!
The 220gr FNFB standard hardcast bullets (BHN of 15) from Rimrock came in on Monday. Grabbed a few of them out of the two boxes, and compared them. Both boxes were incredibly consistent! My grab out of the first box produced 6 bullets. 5 of them weighed 220.0gr and one was 220.1gr. Checked the diameter with my caliper, and all of them are spot on .400" as advertised. I grabbed 5 out of the second box, and every one of them weighed 220.0 grains on the money. Diameter was .400" as well. Needless to say, I was more than impressed with the bullet consistency.
As you guys saw at the beginning of this thread, I did some research before the bullets even got here, and found NOTHING about the 220gr hardcast bullet using Longshot, except for one guy, on one forum, from a few years ago. I can't exactly trust that, but I kept him and his results in mind. I even called Hodgdon and the gentleman said he had no info at all. Three other places said the same thing. Even Rimrock had nothing when it came to Longshot. They had starting loads of about 10 other powders with the 220gr hardcast, but nothing with Longshot. The guy I talked with at Hodgdon was very encouraging. I started telling him about my problem of no load data for the 10mm using 220gr hardcast, especially concerning Longshot. He said, "Funny you mention that, cause I was going to suggest Longshot. It is the best powder we have for 10mm, but that is using 180 and 200 grain bullets. Usually if a bullet weight isn't listed, it is because it isn't recommended." I get that, but at least I felt like I was on the right track since I was looking for Longshot loads, and that was going to be his suggestion. I may eventually go back to 200gr bullets, but not right now -- I'm on a mission.
I decided to work backwards a little bit. I went to the Hornady and Hodgdon manuals. They were so far out of tune with each other that it wasn't even funny. Hornady start load for the 200gr bullet was 5gr longshot, plus or minus a little bit. Hodgdon starting load was around 7gr! Checked a couple more places, and found that 7+/- was pretty common starting point for 200gr jacketed bullets. Being that hardcast is a bit slicker than copper (BHN of 35), I figured starting a little under 7gr of Longshot with a 220gr hardcast would be safe. Just to make sure I wasn't about to stumble in to one of those "hold my beer" moments, I called a friend that has reloaded for years, and ran my idea by him. He assured me I would come back with all fingers, eyes, arms, etc. He and I both shoot hardcast in our revolvers, so I trust his opinion on this. My 45 Colt threw 335gr hardcast using more powder than loads using a much lighter jacketed bullet, so I figured my idea of starting around 7gr with this endeavor would be okay.
I had read that Longshot loads usually perform best at their near max loads. So I loaded up 2 rounds with 6.6gr, 6.8 gr, 7gr, and 7.2gr. I figured I would fire them and look for any bad signs. If all was okay, I'd then start my real testing of 5 shots each of 7.4gr through 8.2gr using .2gr increments. Just to be clear, I checked brass after EVERY SINGLE SHOT as this is unknown territory for me since there is no published data. Everything from 6.6 through 7.2 looked very good. Looked just like fired factory brass. I stopped my ladder at 8.2 because of that guy I kept in mind from the forum I mentioned earlier. His loads maxed out at 8.2 with a "slight smile on one case". So I figured no need to go past 8.2 unless proven otherwise. Turns out, he was pretty spot on!! Here are the results I got:
All loads are with Longshot powder. All loads use Starline brass. All loads use Winchester Large Pistol primers. All loads have a 1.265" COAL. No guns were harmed in the testing of this ammo. HAHA!!
7.4gr Longshot
Fastest - 1167fps
Slowest - 1143fps
Average - 1154
SD - 10
7.6gr Longshot
Fastest - 1188fps
Slowest - 1164fps
Average - 1179fps
SD - 9
7.8gr Longshot
Fastest - 1186fps
Slowest - 1154fps
Average - 1173fps
SD - 13
8.0gr Longshot
Fastest - 1213fps
Slowest - 1185fps
Average - 1198fps
SD - 10
Did not shot 8.2 gr loads. I got flat primers at 8.0gr, and best accuracy was actually at the beginning of the ladder using 7.4gr of Longshot. At 25 yards, I had 4 shots touching at just under 1", and one called flyer that was 2" out because of a pathetic trigger pull. 7.6gr of Longshot gave me a 4" group. 7.8gr Longshot was back to a 2" group, which is more normal for me. (The 1" group I fired with the 7.4gr loads was certainly not my normal, but was very exciting to see. Perhaps I just got lucky.) The 8.0gr loads had the dimple from the firing pin flattened back out, and almost a 5" group. Because of that, I didn't bother with the 8.2gr loads as I was obviously heading in the wrong direction. Found it a bit odd that the average for the 7.8gr loads was lower than the 7.6gr loads, but oh well. See what happens next time out.
To confirm my results, I'm going to do another ladder of 7.4, 7.6, and 7.8 grain loads. I feel very confident that I'm close to having this figured out. Whichever of these three loads I end up with, I'll be more than confident that I can hunt anything in Colorado and not be under gunned. All three of these loads exceed the minimum Ft/lbs energy requirements for hunting that Colorado has.
More to come...
Careful not to batter the gun. 1100 fps will take care of anything that walks if its delivered with deliberate care.
Great results.
https://www.montanabulletworks.com/product/3840-10mm-40-lbt-200gr-lfn-gc/
Or these.
https://www.montanabulletworks.com/product/10mm-lbt-200gr-wfn-pb/
Though i I don’t know how well the latter would feed in an auto.
Zee- certainly gonna keep playing with these loads. I don't feel like I'm anywhere near a dangerous load. I only stopped because the 8.0 group was horrible. Well, I might be getting close to dangerous loads, but I don't think 8.0 is it. I think there is more to play with. And if I mess around with the COAL, the accuracy just might come around. We'll see...
Another interesting thing is that the recoil from these loads felt less than the recoil from the 180gr XTP loads I had been using. Possibly because of jacketed vs hardcast??
My my goal would be 1,200+
I only have one thing left to test with this load, but that test will have to wait till hunting season!!
Now that I have that figured out, I'm going to play around with the COAL and crimp a little bit, and see if I can get an accurate load at 1200fps. Since Zee mentioned that yesterday, I haven't been able to get it out of my mind. I certainly don't NEED it to work as I have found a load I am very happy with. But I just want to know if it CAN work! I can't change the COAL much as I am already almost at magazine max with 1.265" now. But with a little more powder, slightly shorter COAL, or maybe a SLIGHTLY tighter crimp, I can get to 1200fps. I'm not that far away as I'm already at 1179fps, and that is with the lowest of the loads I took yesterday. I think there is more than 21fps wiggle room before I get to warning signs. Just gotta see if I can make it accurate. Getting to 1200+ fps isn't the goal. Getting to 1200+ fps ACCURATELY is the goal. I'll certainly be working in small increments, but I gotta do it. It's for the name of SCIENCE!!
So with that said,
Hold my beer and watch this...
I've also been reading at least one reputable scribe's continued insistence that seating and crimping in two seperate steps make the most consistent ammunition.
That's my game plan for now. So, off to my lab... I mean reloading bench.
A chronograph should confirm it though as long as readings are compared with the two different springs.
The action shouldn't be unlocking until long after the bullet leaves the bore anyway. I could maybe see a little benefit in having tighter lockup, less movement, in some guns. But with stout loads like Buffalo Bore, I'd think the main benefit would be slowing the slide down so it doesn't beat the gun up so much. Not to say that a stronger recoil spring can't help. But I don't think delaying the action unlocking should be an issue as, again, the action should not be moving until the bullet is long gone anyway.
https://www.bing.com/videos/search?q=pistol+fired+slow+motion&&view=detail&mid=F26172EBA871CA8E4FFCF26172EBA871CA8E4FFC&&FORM=VRDGAR
Will be watching this thread!
D
Alcohol, Tobacco, Firearms and Explosives.... now who's bringing the hot wings? :jester:
My stock spring is #18. If I remember right, that BB article talked about a #21. I will see what I can find for my TRP.
We'll right it down and call it science. Otherwise, it's just screwing around!