Chronied 300 Blk Load - Lee 155gr and Lil'Gun

[Gunnut 45/454]

Well I braved the cold -20 degrees- to get the data on my Cast Lee 155 gr load of 16.5 gr out of my 16" carbine. I was a bit surprised to see an Avg 2023 fps I was thinking of in the mid 1900's even though I see no pressure problems primers looked fine. Though I didn't shoot for accuracy it still looks to be a very accurate bullet in my rifle, I also shot some in my '06 Rem 7400 and they are very accurate in it.

300 Blk 16" Carbine 1:8" twist.

Load Data:
Lee 155 gr GC
Case Fed 223 1.360"
Fed SR Primers
16.5 gr Lil'Gun
COAL- 2.065"

Avg. 2023 fps SD 14.4 ES 15

1. 2017 fps
2. 2044 fps
3. 2017 fps
4. 2038 fps
5. 2002 fps
6. 2036 fps
7. 2030 fps
8. 1998 fps
9. 2008 fps
10. 2042 fps

In light of this I'm going to try a different load as in seat the bullet to the crimp groove and reduce the load to 16 gr. As I saw some movement in COAL of rounds in the mag. so I want a light crimp going forward. Dropping down to 16 grs an with a new shorter COAL I should be right around the same velocity. We are hopefully going to warm up some this week and next so I'll update soon.:mrgreen:

[45 2.1]

I would be careful and try the same thing when it's warm. You may get a surprise involving more pressure then.

[Jailer]

You'll definitely have more pressure and speed. That same load in my bolt gun in warmer weather runs about 120 FPS faster and had some very distinct pressure signs.

Back it down a little bit and you'll be pleased with the accuracy that comes with it.

[Gunnut 45/454]

Yep I have backed it down to 16 gr. Now I run Jwods 150 gr at about the same speeds with zero pressure signs. Since Lil'Gun runs at lower pressures to begin with so I'm not to concerned. Shorten the COAL to 2.015" to get to the crimp groove so I could put a slight crimp on them.

[2wheelDuke]

As soon as I clicked into this thread, I thought 16.5 sounded a little hot. I was very interested because I've been loading Lil Gun behind that same boolit.

I was given 16.0 as a start, and advised to "work up." I wasn't sure where the limit was really. I did try 16.2 and they shot well, and I don't see any signs of excess pressure yet. I haven't chrony'd yet. The 16.2 were shot on a 70-something degree day in S. Florida. Accuracy was decent enough from what I've seen of the upper so far, and besides a little powder fouling, it looks shiny and clean down the bore.

[Gunnut 45/454]

Well I got and Chronied the 16gr load. Data as follows.

155gr Lee cast
16gr Lil'Gun
Fed .223 case 1.360"
Fed SR primer
COAL 2.015"

Avg. 1984 SD 10.8 ES 14.5 Temp 47 degrees.

1. 1974
2. 1970
3. 1997
4. 1970
5. 1980
6. 1980
7. 1997
8. 2009
9. 1988
10. 1977

[Jailer]

Did you check accuracy or just shoot them over the crono?

[Gunnut 45/454]

59573
Jailer

Here's the target shot at 50 yards- I wasn't shooting for group but not bad.

[3006mv]

i shot a few pc 155 in my 300 whisper with 15.5 gr H110. they shot much higher than my 230 gr lee which is what my scope is dialed in for. it was 90 F here in so ca today