Working Up Loads for an Encore Pistol

[riverwalker76]

I've been working up loads for my TC Encore .223, and am now moving on to my .308.

The problem I'm having is that there is no published data using IMR 8208 XBR and a single shot pistol.

Lyman, Sierra, and Hornady all have a "TC or Single Shot Pistol" section, but they don't list information for this powder.

Can I work off of the IMR data for the same bullet weight and a standard rifle barrel? I other words .... will 24" barrel data be ok to use on a 15" barrel?

 

[T. O'Heir]

"...there is no published data using IMR 8208 XBR..." Very likely a good reason too. Isn't listed for .308 handgun loads by Hodgdon either. Likely doesn't burn fast enough for a short barrel.

 

[riverwalker76]

That can't be the reason!

Sierra lists both H4198 & Win 748 data for this study.

8208 XBR is right, smack dab, in between the two as far as burn rate.

h4198 = 72

8208 XBR = 85

Win 748 = 101

http://www.imrpowder.com/burn-rate.html

Win 748 is the slowest of the powders tested, and it is the most accurate.

If anything ... the pistol barrel prefers the slower powder.

 

[PCJim]

RiverWalker, you "can" use the rifle data for working up a load for your Contender, however it may not give the best results. If you're intent to use it, start low and work up slowly. You will not develop the same velocity in your 10/14" Contender as you would in a full length rifle barrel. You will also probably see unburnt powder as the shorter length barrel will probably not give enough time for a complete burn of the powder.

While your desired powder, 8208 XBR, may fall between the other two powders in the burn chart, it does not mean that it is ideal for this particular use. Powder manufacturers test many, many powder/charge level combinations for all calibers/bullet weights. Imagine the potential number of listings that each manufacturer might provide if they listed all their testing data. They only publish those powders that provide the best results across the board, with the least amount of liability (read: developed pressure).