Duplicating Buffalo Bore FBI Load

Hoptob

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For awhile now I’ve been impressed with Buffalo Bore awesome 158 gr. lead SWCHP 38 special load (#20A). Clocked at over 1040 fps from 2” bbl and 1160 fps (!) from 4” bbl, BB FBI load is without a doubt the most powerful 38 special load on the market today. Who says 38/44 is a thing of the past?

As a reloader I always wanted to replicate it. What does it take to get this type of ballistics in 38 special? Can it be done within +P limits? Tim Sundles who developed this load used to post on THR. People often asked him these questions. Tim provided some information but it only added to the mystery around his load. Over time Tim stated that:

  1. BB #20A load is within SAAMI pressure limit
  2. It is safe to fire it in any modern 38 special +P revolver in a good operating condition
  3. He uses flash-suppressed non-canister powder which is not available in stores
  4. To protect BB trade secrets he will provide no further information
A few months back a member of this forum, 336A, posted that Rimrock Bullets Co. sells 160 gr. soft lead SWCHP bullets used in BB load – link. Thanks, 336A! I bought some of them and can confirm that it is in fact the same bullet.

With the right bullet in hand, my BB FBI load duplication project was off to a good start. First things first – I broke one of the BB rounds. Inside the case I found 7.5 gr. of a flake powder. It looked somewhat similar to SR4756 but it wasn’t same. Below are close-up shots of the two powders taken at 11x magnification. You will see that BB flakes are smaller and thicker than SR4756.

TSBL_powders1.jpg


Looking at these pictures someone may wonder if they were taken with an expensive lab microscope. Nothing of the kind, folks. I used my trusty 8 y.o. consumer digital SLR equipped with 20 y.o. 50 mm Nikon lens ($85 at the time) and a set of extension rings worth $60 NIB. It’s honest backyard science, folks, no cheating :)

Now, BB load is charged with 7.5 gr. of powder. We can assume that it must be one of the medium burn rate powders, not the likes of Bullseye or 2400. After studying recent and not so recent manual, I chose four powders to work with – HS-6, Longshot, SR4756 and VihtaVuori N340. All handloads were built as close as possible to BB load, except for less crimp. I did apply firm crimp but stopped short of making crimp line simply to extend service life of my brass. I found that bullets were held very securely without excessive crimp. It took over dozen good hits with Dillon bullet puller to break these rounds; normally I consider 5-6 hits to be good enough.

TSBL_rounds.jpg

Buffalo Bore FBI load (left) and handload (right); Rimrock 160 gr. SWCHP. All handloads were made with Rimrock bullets,
S&B 38spl cases; OAL 1.46”; firm crimp. Primers: Rem 1-1/2 in N340, Longshot and SR4756 loads; Win SPM in HS6 loads.


BB load clocked 1044 fps in my 2-1/4” bbl SP101 – exactly as advertised. After several extended load-building and chronographing sessions, I found out what powder charge is needed to get same velocity in my handloads. Here it is:

TSBL_charge.gif


Here you have it - four replicas of Buffalo Bore FBI load.

For those who want cheaper training load – I suggest that you try TVB 158 gr. SWC instead of Rimrock SWCHP. Rimrock makes wonderful soft hollow point bullet. It's close to perfect for self defense snubby loads but it is also rather expensive as far as training goes. I see no reason to punch holes in the paper with a $18.50/100 lead slugs. TVB bullets sell for almost 3 times less; in my tests they clocked at almost same velocity as Rimrock's and produced no leading at BB velocities. TVB bullets are available from a member of this forum Jessie aka NKJ Nut - Tennessee Valley Bullets.

Naturally, all of my BB replicas were well above published load recommendations for 38spl+P. FWIW, pressure calculations placed HS-6 and Longshot loads in 26,000-27,000 range; N340 and SR4756 were running a bit higher. Primers showed moderate deformation consistent with this range of pressures.

TSBL_primers.jpg


Does any of this mean that BB load has to be above +P pressure limit? Not at all. It is entirely possible that Tim Sundles’ secret flake powder allows him to reach 38/44 ballistics with 38spl+P pressures. The only way to find out would be to have his load tested by H.P. White or another reputable lab.

DetSpl3.jpg


I have to say that I am not too concerned with the load pressure. My steel frame Colt Detective Special is quite happy with Buffalo Bore FBI load. And so am I.

Mike
 
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Very interesting report. Well thought out and executed. Thanks for sharing this info.
 
I haven't read the whole thing yet, work you know!

Mike,
I wonder if you need to take a look at SR7625. That powder is very close to what you have in the Buffalo Bore photo. I'll take a picture of some of mine when I get home!

Just a thought.
 
Not sure!

Well, I got home and took a picture of SR7625 and the more I look at it the less I think it matches.

Click on the attachment to view the picture. See what you think. What about someone that has some Alliant Power Pistol taking a picture of that and posting it.

Mike,

You are my hero when it comes to these reports. I may have video in mine but you really have the data! How about an amazing chart or two! ;)
 

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HopTob,

Thanks for the information. Well done and excellent presentation.

Do you by any chance shoot .380 Auto? I would be interested in duplicating BB 380 loads. Here in hot Florida with light clothing a .380 is always with me and coordinates well with my Speedo.:)

The only powder I have that looks a bit like the BB powder is Blue Dot??
 
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Thanks for the good words, guys. Glad you found my BB replica project helpful. When it comes to reporting -- I am learning from the best.

Skip, nice picture of SR7625! What "microscope" are you using? Turns out making great video's is only one of your virtues :)

To me the the two powders look very similar. However I don't think BB uses SR7625. Based on Hodgdon tables SR7625 is faster than SR4756 (about 1 gr. or so) while BB powder is 0.5 grain slower.

As far as the charts go... I am working on an article for "The Journal of Backyard Ballistics"; there will be a plenty of charts there :D. In the meantime -- check your email. :)

Mike

P.S. Thanks, OCD! Sorry, I have no data on BB 380 Auto load and no experience with this caliber. I hear it's a good one. James Bond used it, it must be good enough. :) Just haven't gotten around to try it myself. -Mike
 
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Thanks for the extensive report, I know how much work went into developing it. I gave a FBI Load replica load I use which is 7.0gr HS-6 with a 158gr LSWC/HP bullet and a Magnum SP primer. I'm fairly sure that load is within the 20,000 PSI limit and I get just about 900 fps from a 2" barrel. (889 fps average) I'm wondering what 7.5gr HS-6 would do considering that's the charge in the BB load. I use a Hornady bullet without a gas check and there's no leading in my FBI replica.
 
Great points as always, Tony. I should have mentioned in my report that this project builds up on excellent FBI load development work that you, Jim and others have done and posted before.

In fact my favorite powder for this application is same as yours - HS6. First of, it's old, tried and true powder. When you use it, you don't expect unpleasant surprises such as unexpected pressure spikes, excessive temperature sensitivity, etc. There is a lot to be said for using same powder as generations of reloaders used before you.

Based on my pressure calculations HS6 reaches BB velocities at the lowest pressure point among the powders I tested. Of course, calculations are just that - calculations. They could prove inaccurate but that's the best I've got. With 160 gr. soft RB bullet and 2-1/4" SP101 (fast gun with slightly longer barrel than 2" you used) I got following numbers:

6.3 gr. HS6.....843 fps....16,200 CUP (Hodgdon max charge and pressure)
7.0 gr. HS6.....928 fps....19,900 CUP
7.5 gr. HS6.....986 fps....22,800 CUP
8.0 gr. HS6....1042 fps....25,900 CUP

Note that even though BB round is charged with 7.5 gr. of a powder, it is a different powder than HS6. It took 8.0 gr. HS6 to replicate BB velocity. I sent some additional information to your yahoo email address.

Another interesting connection here is that 8.0 gr. HS6 under 158 gr. lead bullet is... That's right, it's the maximum load recommendation for 38 special from Speer #8. ;)

Mike
 
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Great points as always, Tony. I should have mentioned in my report that this project builds up on excellent FBI load development work that you, Jim and others have done and posted before.

In fact my favorite powder for this application is same as yours - HS6. First of, it's old, tried and true powder. When you use it, you don't expect unpleasant surprises such as unexpected pressure spikes, excessive temperature sensitivity, etc. There is a lot to be said for using same powder as generations of reloaders used before you.

Based on my pressure calculations HS6 reaches BB velocities at the lowest pressure point among the powders I tested. Of course, calculations are just that - calculations. They could prove inaccurate but that's the best I've got. With 160 gr. soft RB bullet and 2-1/4" SP101 (fast gun with slightly longer barrel than 2" you used) I got following numbers:

6.3 gr. HS6.....843 fps....16,200 CUP (Hodgdon max charge and pressure)
7.0 gr. HS6.....928 fps....19,900 CUP
7.5 gr. HS6.....986 fps....22,800 CUP
8.0 gr. HS6....1042 fps....25,900 CUP

Note that even though BB round is charged with 7.5 gr. of a powder, it is a different powder than HS6. It took 8.0 gr. HS6 to replicate BB velocity. I sent some additional information to your yahoo email address.

Another interesting connection here is that 8.0 gr. HS6 under 158 gr. lead bullet is... That's right, it's the maximum load recommendation for 38 special from Speer #8. ;)

Mike

More interesting is that the charge of 4756 it takes to duplicate the BB load isn't the max .38 special load in the #8 :eek:
 
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