Barnes 200gr XPB and 275gr TSX

Talk about your 450b reloading experience, ask questions, etc...

Moderator: MudBug

Forum rules
Please try and keep it safe!

This information is the responsibility of the community, not the forum. 450bushmaster.net is not responsible if you blow yourselves up.

Re: Barnes 200gr XPB and 275gr TSX

Postby Bmt85 » Tue Jul 25, 2017 2:30 am

Do you notice any signs that your over pressure? What was your CHG for 39gr of Lilgun?

The Lyman AR manual shows 39gr of Lilgun as a starting point with a velocity of 2328fps out of a 16" barrel. It's been said that current Lilgun is hotter than older Lilgun. So that could explain some of the increase, but your numbers for the 200 XPB still seems a bit high. With that said, I have a 16" Bushmaster upper, I run the 200 XPB with 43.5gr of Lilgun (current production) and a stab crimp. No pressure signs, and CHG is good (don't have the numbers in front of me at the moment). Don't have velocities, sorry.
Bmt85
 
Posts: 191
Joined: Wed May 18, 2016 11:13 am
Location: S.E. Michigan

Re: Barnes 200gr XPB and 275gr TSX

Postby Hoot » Tue Jul 25, 2017 4:59 am

Bmt85 wrote:Do you notice any signs that your over pressure? What was your CHG for 39gr of Lilgun?

The Lyman AR manual shows 39gr of Lilgun as a starting point with a velocity of 2328fps out of a 16" barrel. It's been said that current Lilgun is hotter than older Lilgun. So that could explain some of the increase, but your numbers for the 200 XPB still seems a bit high. With that said, I have a 16" Bushmaster upper, I run the 200 XPB with 43.5gr of Lilgun (current production) and a stab crimp. No pressure signs, and CHG is good (don't have the numbers in front of me at the moment). Don't have velocities, sorry.
.

Wat Bmt85 said and I'll add one tidbit. I'm not sure about your recent weather, but we have had some withering hot days up here lately, which is to be expected in late July. All ball powders get hotter when the temperature gets hotter and 39gr is approaching the high end anyway. I usually wait out the hot time of the year, opting to doing 450b load work in the spring and fall. I usually hunt on the winter, so my loads are developed in cooler conditions. Pushing 200gr XPB's to 2600fps is not endangering your rifle, but is getting up there. I wouldn't be surprised if that same load velocity drop to 2400's under fall conditions. Some bores are tighter fits ad some are looser. You may have a tighter bore. That jacks up the resultant velocity also.

Hoot
In Theory, there is no difference between theory and practice. In Practice, there is.
User avatar
Hoot
 
Posts: 3588
Joined: Tue Feb 09, 2010 9:34 am
Location: Minnesota

Re: Barnes 200gr XPB and 275gr TSX

Postby Texas Sheepdawg » Tue Jul 25, 2017 5:36 am

Fine work there, mcb. These are the two bullets that are next up on my range testing. I already have them loaded and ready. I just need to find the time. My crimps will be different however and my OAL may differ greatly on the 275s as I loaded them to be shot out of my bolt action plus I'm using 1680 for the powder charge.
-Texas Sheepdawg
Join us on FaceBook https://www.facebook.com/groups/Texas.Sheepdawg.Patriots/
http://youtube.com/c/TexasSheepdawg21
NRA Life Member
User avatar
Texas Sheepdawg
 
Posts: 4050
Joined: Fri Nov 05, 2010 10:55 am
Location: North Texas

Re: Barnes 200gr XPB and 275gr TSX

Postby mcb » Tue Jul 25, 2017 8:38 am

Hoot wrote:
Bmt85 wrote:Do you notice any signs that your over pressure? What was your CHG for 39gr of Lilgun?

The Lyman AR manual shows 39gr of Lilgun as a starting point with a velocity of 2328fps out of a 16" barrel. It's been said that current Lilgun is hotter than older Lilgun. So that could explain some of the increase, but your numbers for the 200 XPB still seems a bit high. With that said, I have a 16" Bushmaster upper, I run the 200 XPB with 43.5gr of Lilgun (current production) and a stab crimp. No pressure signs, and CHG is good (don't have the numbers in front of me at the moment). Don't have velocities, sorry.
.

Wat Bmt85 said and I'll add one tidbit. I'm not sure about your recent weather, but we have had some withering hot days up here lately, which is to be expected in late July. All ball powders get hotter when the temperature gets hotter and 39gr is approaching the high end anyway. I usually wait out the hot time of the year, opting to doing 450b load work in the spring and fall. I usually hunt on the winter, so my loads are developed in cooler conditions. Pushing 200gr XPB's to 2600fps is not endangering your rifle, but is getting up there. I wouldn't be surprised if that same load velocity drop to 2400's under fall conditions. Some bores are tighter fits ad some are looser. You may have a tighter bore. That jacks up the resultant velocity also.

Hoot


Bmt85, what do you mean by CHG in your first sentence. I thought CHG = Charge and for that last load I was concerned about it was a Charge of 39gr of Lil'gun under that 200gr PBX. I suspect you mean something else. I couldn't imagine what 43.5 gr of Lil'gun would be like under that bullet. That has to be smoking.

The fact that I got the significantly higher velocity than I expected is why I am asking questions. Quickloads was predicting ~2418fps for my 20 inch barrel if I shorten the barrel to 16 inches the prediction lines up very close to what your Lyman manual states. When I got a touch over 2600fps I got concerned. Most of my other loads have been much closer (give or take 50-60fps or less) to other published data and/or Quickload predictions than this particular load.

I did not notice any pressure signs but I will look at the brass again tonight and take some measurements. I write the charge weight on the brass with a sharpie when working up new loads so I should be able to identify the cases.

Hoot, you may be onto something with the temperature. I did not think about that. It was mid afternoon and was easily 95 degree in Tennessee where I was shooting. The gun was hot too. That 39gr loads was fired right after the two five-shot test loads for the 275gr loads and the five-shot test of the 37.5 gr 200gr PBX load. Everything was hot.

Texas Sheepdawg wrote:Fine work there, mcb. These are the two bullets that are next up on my range testing. I already have them loaded and ready. I just need to find the time. My crimps will be different however and my OAL may differ greatly on the 275s as I loaded them to be shot out of my bolt action plus I'm using 1680 for the powder charge.


Please post your results with the 1680 powder when you get them. The local Cabelas carries that powder and I would be curious to see what results you get with it under that 275gr bullet.
Last edited by mcb on Tue Jul 25, 2017 11:06 am, edited 1 time in total.
User avatar
mcb
 
Posts: 70
Joined: Fri Apr 07, 2017 10:22 pm

Re: Barnes 200gr XPB and 275gr TSX

Postby Texas Sheepdawg » Tue Jul 25, 2017 9:13 am

The current OAL for the 275s is too long for the AR platform but they have fed well in my bolt action. I only fired one shot at a steel plate at 50 yards just to check recoil and it Thwacked the tar out of that plate. But as you guys are aware.... It's HOT here in texas right now so I'm waiting for cooler temps to test.
Here's a pic of the 275s.
IMG_7369.JPG
275
IMG_7369.JPG (1.8 MiB) Viewed 528 times
-Texas Sheepdawg
Join us on FaceBook https://www.facebook.com/groups/Texas.Sheepdawg.Patriots/
http://youtube.com/c/TexasSheepdawg21
NRA Life Member
User avatar
Texas Sheepdawg
 
Posts: 4050
Joined: Fri Nov 05, 2010 10:55 am
Location: North Texas

Re: Barnes 200gr XPB and 275gr TSX

Postby mcb » Tue Jul 25, 2017 9:22 am

Yeah my Barnes have to be shorter to fit in my magazine. What bolt gun is your 450BM?

Image

Far left is the 200gr PBX seated so the case mouth is just below the forward groove. I did not want the case mouth to crimp into the groove. Next cartridge is the 275gr TSX and you can see its seated over all the grooves in the bullet.
User avatar
mcb
 
Posts: 70
Joined: Fri Apr 07, 2017 10:22 pm

Re: Barnes 200gr XPB and 275gr TSX

Postby Texas Sheepdawg » Tue Jul 25, 2017 11:25 am

mcb wrote:Yeah my Barnes have to be shorter to fit in my magazine. What bolt gun is your 450BM?

Image

Far left is the 200gr PBX seated so the case mouth is just below the forward groove. I did not want the case mouth to crimp into the groove. Next cartridge is the 275gr TSX and you can see its seated over all the grooves in the bullet.


Ruger American 16" love the magazine. Very roomy.
-Texas Sheepdawg
Join us on FaceBook https://www.facebook.com/groups/Texas.Sheepdawg.Patriots/
http://youtube.com/c/TexasSheepdawg21
NRA Life Member
User avatar
Texas Sheepdawg
 
Posts: 4050
Joined: Fri Nov 05, 2010 10:55 am
Location: North Texas

Re: Barnes 200gr XPB and 275gr TSX

Postby Bmt85 » Tue Jul 25, 2017 2:31 pm

MCB,

CHG stands for Case Head Growth, also called Case Head Expansion. Here's some info on it. http://450bushmaster.net/viewtopic.php?f=5&t=12865
Basically take a few measurement just above the extractor groove, with a mic (I use a blade mic), before and after firing. the difference between the before and after is your Case Head Growth, or Expansion. I also track my brass length.

I agree with what Hoot said about the heat. So I believe your velocities were from Lilgun being hotter, a hot day, and a hot rifle. Which could get you into trouble really quick if your not paying attention. However, I have a feeling you should be fine, just check your measurements.
Bmt85
 
Posts: 191
Joined: Wed May 18, 2016 11:13 am
Location: S.E. Michigan

Re: Barnes 200gr XPB and 275gr TSX

Postby mcb » Tue Jul 25, 2017 2:46 pm

Thanks Bmt85, I will do some measuring tonight and let you guys know. Thanks for all the feedback! I am also going to start a thread about that far right round in the picture I posted above. It's been an amusing load to work up so far.
User avatar
mcb
 
Posts: 70
Joined: Fri Apr 07, 2017 10:22 pm

Re: Barnes 200gr XPB and 275gr TSX

Postby Bmt85 » Tue Jul 25, 2017 3:35 pm

Resized Remington 405gr?
Bmt85
 
Posts: 191
Joined: Wed May 18, 2016 11:13 am
Location: S.E. Michigan

PreviousNext

Return to Reloading for the 450b

Who is online

Users browsing this forum: Bing [Bot] and 6 guests