Too much powder?

[Rottentofu]

Hogdon recommended 18.5gr of H110 for 125gr bullet for 300 blackout. I loaded 18.0gr of powder and something went wrong. Please see below. Was it because I used too much powder?





I found the primer stuck inside the feed ramp.

[baih777]

Clean your bolt real good and check for cracks. You got lucky. Work your load up from 15g and go up from there.

[TKM]

Hogdon lists 17.8 as max.

[divingin]

Actually, Hodgdon's data center recommends 18.5 as a max load. That is kind of a "do not exceed" load. Pretty foolish, IMO, to jump in just below that.

Start where the data says "Starting Load" (there's a reason it's called that), and work up from there.

[ironhorse1]

It is very apparent that you managed to exceed maximum cartridge pressure.

While Hodgdon does list 18.5 grains as maximum and a compressed load to boot there is definitely a problem with your load.

Pull any rounds you have left and re-weigh the powder. Be sure that the powder was in fact H110.

Was the bullet loaded to beyond max length possibly jammed into the barrel lands?

Did you use a small rifle magnum primer? Re-check your bullet weight.

Finally the starting load is listed as 15.7 grains. I might have been better to start there and work up your load first.

irh

[Rottentofu]

Yea, definitely gonna start with 15gr. I double checked everything. Primer, OAL, and powder weight are all correct. But I am pulling all the 18gr powder rounds.

[JackEllis]

I recently worked up a load for my .30-06 using 150 grain GMX bullets and IMR4064. Hornady lists the max load at 55.6 grains to yield 3000 fps. I started at 50 grains and was seeing 3000 fps and pressure signs (slight flattening and cratering of the primer) at 52.5 grains.

If I didn't quite appreciate why it's called "working up" a load when I started doing this, I sure appreciate it now.

[Kwikvette]

Lyman's 50th suggests 16.8 starting and a max load of 17.8.

Also suggests 1680 between 19.5 and 21.5 for potentially the most accurate (Sierra HP match projectile).

[bigdawg86]

I have converted about 5k of GI brass for 300 BLK... I noticed that with the mixed brass (often age or reloading status unknown) loose primers would present themselves. I haven't used H110 but have maxed out loads with Lil Gun and had results that were similar... not due to insane pressures, but likely due to worn brass that was converted. That's my take at least. I figure if the load data, barrel length, bullet weight, and charge are lining up with the book but I blow a primer, I wonder if it was the brass reload life being an issue more than the load.

[bazineta]

Loose is one thing...blown into a little chefs hat, that's another.

[LynnJr]

If your primers seated without any effort you will get that same result.
Was this a bolt gun or semi?

[Sheldon]

From the brass flow into the extractor groove on the casing I would say the load combination was too hot for your rifle. Reloading manuals are a reference and the pressures listed in them are for the specific combinations of components and barrel. Working up the load is the prudent way to go. Glad you didnt get hurt!

[Rottentofu]

If your primers seated without any effort you will get that same result.
Was this a bolt gun or semi?

Semi

[J-cat]

Be mindful of case volume differences between brands. They contribute to excessive pressure.

[McGuiver]

Too much powder?

I can't tell from the picture what head stamp that 300 AAC converted brass has. Be careful with bulk converted brass. There is a general list of what is acceptable for use because of case neck wall thickness. Excess case neck wall thickness usually keeps it from chambering, but there have been guns blown apart due to excess pressure from this. Glad OP is OK.

If you want you can use a tubing micrometer to measure the case wall thickness.

http://www.300blktalk.com/forum/viewtopic.php?t=88599

Something similar to this helps measure the neck wall thickness...

http://a.co/jl7PBLA

Here is a good write up about measuring the necks on converted brass...

http://www.massreloading.com/300BLK.html

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