Motorhead Tune Review - RWS Diana 56 Target Hunter

Many of you read and commented on the review I posted now several weeks ago of my new .22 RWS Diana Target Hunter. Though a really "good" performer out of the box, as my review stated, the shot cycle was pretty harsh/violent, the report very loud, and the trigger - while usable, was not great. Accuracy was very acceptable for such a powerful spring rifle, but I thought it could be better. So, always wanting the most from my rifles, I packed it up and sent it to Scott Schneider at Motorhead Airgun Tuning Services, about 48 hours before the airgun world went nuts after receiving word that Scott may be joining the JSAR group and closing down his tuning business.

Scott acknowledged receipt of my rifle right away, but was straight-up with me that with all he had going on at the moment, it might be sometime getting it back. Having had Scott now tune five of my rifles, I can't think of anyone else I really wanted to touch it, and decided it was worth the wait. I am not disappointed in that decision.

My rifle arrived back on 12/27. As you will see below, Scott advised in his initial after work report that the barrel lead and throat were too large, something I had commented on my initial review, indicating that the 5.53 pellet head sizes would likely perform best. This thought was backed up by my out-of-the-box tests at both 18 and 50 yards (indoors). I had also noted that one had to be careful not to allow the 5.52 head size pellets to fall out in the loading process. Scott's validation of this was a real concern to me, thinking I might have received a "lemon" as the barrel is not a replaceable part.

What follows are various exhibits that illustrate my findings and the performance/handling comparisons between the out-of-the-box tests and post Motorhead tests. Was it worth the effort and investment? I always say this is answered by asking oneself "if I had to do it over again, would I do the same thing?" The answer in this case is "absolutely."

  • Exhibit 1 - in Scott's own words, you will find the work that was performed to complete the "Tune." The trigger went from good to fantastic. The shot report is much less harsh and offensive. The shot cycle is very smooth. You will note that Scott indicates that this rifle's accuracy will be limited to 5.53 head size information. Based upon my original out-of-the-box testing, again, this was no surprise. As you will see from the post tune testing, Scott and I were both wrong about this. Proof that one HAS to TEST every rifle to find its preferred round. Each rifle will have one.
  • Exhibit 2 - a statistical before and after tune comparison. The three pellets indicated were the three best performing pellets during the previously conducted out-of-the-box review tests. Note that the lowest standard deviation of 2 fps over a twenty shot group was achieved post tune - something many PCPs will not achieve. Best lowest average group sizes at 18 yards and 50 yards shrunk by 42% and 31% respectfully after tuning. The most accurate pellet combination (AA 18.0 grain 5.52mm) FPE only reduced from 21.6 to 20.5 ft lb.
  • Exhibit 3 - chronograph comparative results for 20 shot groups, for each of the three pellets tested, before and after tuning. The three pellets tested throughout this review were the H&N Field Target Trophy 14.66 gr (5.53mm), the Air Arms Diablo Field 18.0 (5.52) as I always find that they are more consistent in weight and head size than are the JSB equivalents, and the H&N Baracuda Match 21.14 grain (5.53.)
  • Exhibits 4, 5, 6, 7, 8, and 9 show the actual two 10 shot test groups fired for each pellet, at both 18 and 50 yards - indoors. The temperature of the 18 yard range is a constant 65 degrees - the 50 yard range is heated to 45 degrees this time of year. Note that the AA 18 grain pellet was the real surprise, coming in with a two 10 shot group average of only 1.02" at 50 yards - again, many pcps cannot accomplish this.
  • Exhibit 10 - to shoot the groups found in exhibits 4-9, I used my rifle as sighted in for the Baracuda 21.14 grain pellets at 18 yards, then shot groups at 50 yards to determine where the corresponding mil-dot hold over needed to be. It is a good comparison to see the group sizes that resulted from these tests, as compared to the results in exhibits 7,8,& 9 - sort of a validation or verification if you will. Note the AA was again the best, shooting a group of only .92" while the anticipated pellet to be the best performer - the Baracuda Match, was actually the worse group, of 1.95."
  • Once I determined that the AA 18 grain pellet was the most accurate in this rifle, I re-sighted in the rifle with this pellet at 18 yards (I used 18 as it is the distance available on my indoor home range - making it easy to keep my rifles all calibrated). Then I hold dead on and move back shooting groups at five yard intervals from 25 yards, until such point as the groups open up to beyond 2". I believe that the maximum effective range for any air gun is where the gun shoots <2" groups. Some very interesting results are indicated on this page.
    • As I have already indicated how the groups look at 50 yards, I thought you all might like to see what happened beyond 50. The groups shown are actual. The 60, 65, and 70 yard groups were amazing, though none of them were more than 5 shots. As I was working to determine POI, once consistency was evident, I moved on.
    • More notable, as with all of my rifles, there is always a point where the groups just totally disintegrate. For this rifle, it occurred at 75 yards. Note that it took 20 shots to establish a significant enough core for me to use as a hold over point. As such, I believe the maximum effective range or this rifle is approached at 75 yards.

In summary, I more than got my money's worth from Scott's efforts, plus he is just a joy to deal with, a true professional, and a great human being. With care, this rifle should last a long time and as a powerful side lever, holds a unique place within my collection.

Enjoy and good shooting!

DZ

1578021665_9352107745e0eb321f25088.50595279_1.Work completed.Motorhead.12.27.19.jpg
1578021666_10287356345e0eb322782954.61421502_2.Post Tune Performance Summary Table.jpg
1578021666_11737824685e0eb322ce9cd6.17239307_3.OOB-Post Tune Chrono Comparisons.jpg
1578021667_17042036415e0eb32309bc23.16662808_4.18 yard H&N 14.66 Gr comparisons.12.30.19.jpg
1578021667_4059433045e0eb3232157b8.79690747_5.18 yard AA 18.0 comparisons.12.30.19.jpg
1578021667_11369578865e0eb3234520c3.51929403_6.18 yard H&N Baracuda Match 21.15 Gr comparisons...jpg
1578021667_19044623855e0eb3235e6156.45885588_7.50 yard H&N 14.66 Gr comparisons.01.01.20.jpg
1578021667_10489469905e0eb3237f9421.44166867_8.50 yard AA 18.0 Gr comparisons.01.01.20.jpg
1578021667_10477515135e0eb323949712.12419863_9.50 yard H&N Baracuda Match 21.14 Gr comparisons...jpg
1578021668_11857854995e0eb324501ec8.26434076_10.50 yard POI Group Sizes.01.01.20.jpg
1578021669_13636902885e0eb325347aa5.60846313_11.60-75 yard elevation test results.01.01.20.jpg