Sims Barrel Deresonator Test

What we are after is a fix for problem barrels that exhibit poor accuracy. If barrel harmonics can be eliminated in the process of finding the true cause of inaccuracy, then a better guided course of action can be taken in choosing what remedial action is necessary.

In other words, if there are other problems in the system, such as loose hinge pin fit, too much or too little headspace, or forend bedding problems, all the rechambering in the world is not going to fix these problems. 

You can have a $500 custom barrel with a perfect chamber and throat and still not get good accuracy if there are other deficiencies.

Charlie's results below are from barrels that shoot well to start with.... the only ones he keeps..... and in this situation, just the reverse of what is expected occurred. He experienced degraded accuracy instead of improved. We are waiting for reports from the other two testers, one of which has indicated improvements so far.

Before and after groups.

Larger group circled lower left is with the De-Resonator installed. Sub-inch 3-shot group to the right is without the De-Resonator.

 This was a barrel I rechambered for Charlie, a factory blued barrel

Charlie's Report

Afternoon Mike,

Just returned from wringing out the Sims allegedly small group inducer. Four hour and almost a 100 assorted rounds. Bottom line I think it is

a gimmick. If you will look at some of my targets the 300 H & H that you rechambered actually opened up when the rubber doohickey was on the barrel. It by the way is very capable of shooting one hole groups sandbagged at 100 yards if I do my part. The first three shots in a heated barrel and

going for record included two bullets in one slighter larger hole. Adding the rubber... not only made my rifle look ugly it opened up the group. I stuck to three shot groups because I figure guys want this for hunting and three shots is all they will ever get. 

So I tried it on a 30 inch fluted VV 338 Galaxy barrel. It did not tighten groups but moved them two inches to the left of point of impact...so it does do something with harmonics. I tried it on the end of the barrel and next to the forend...with little difference in accuracy. Putting on a 30-30 with a folding stock opened my groups. On a 300 Win Mag with a folding stock no difference. I

f you have another volunteer I would be very happy to send this thing to them...

it is not something I want to pack around in the woods.

Hope this helps.

 Regards Dr Charlie

And Another Similar Report

Sorry for the delay but deer hunting come first. I'm very disillusioned with the performance of my only TC rifle barrel with or without the deresonator. I therefor selected the most accurate barrel in my arsenal and proceded with testing. Tested was a Browning single shot with 26" octagon barrel in 6MM Rem Cal. The resuls are attached. Identical conditions were used in both sets of shots with cool down between shots. Results are attached and speak for them selves.